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Re: MFR3 with TMB130SS

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  • MallinCam
    Dom and all, We have covered this before several times on this list in past post. So, I ;ll sound like an old broken record again. (i don t mind) The MFR-5 was
    Message 1 of 20 , Jun 26, 2012
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      Dom and all,

      We have covered this before several times on this list in past post. So, I';ll sound like an old broken record again. (i don't mind)

      The MFR-5 was design with two cells of two lenses each working together to achieve a low F/ratio from ANY telescope except a Newtonian type optic to deliver a lower F ratio. First set of lens (front part) is a 0.5.5X reduction and seconds is a CCD CORRECTOR field Flatner made FOR CCD of 1/2" in size only or 0.8X. The amount of reduction can vary from F/2.8 all the way to F/4.5 depending on optics used on. as tested on a optical bench and in the field.

      Using a series of spacers where greater distance will change this reduction can be pin point for optimal position between the ccd sensor and MFR-5 to deliver a specific final F ratio.


      It was mainly design for people who wanted to use a focal reducer with a diagonal to clear the way of the camera when used on a SCT in ALT-AZ just like my own SCT. But, the MFR-5 can be used as well at prime focus through a rear cell adapter of a SCT.

      Distance between smaller MFR-5 cell and ccd sensor will dictate the amount of vignetting, amount of uncorrected star field. The MFR-5 picks up what you feed it. If optics are of not "normal range", expect some artifact which needs to be corrected by removing all spacers from the MFR-5. Infrared can also play havoc on final reduction on some refractors and curvature of optics as well will result in artifact. Less reduction is then desired.

      MallinCam developed the MFR-5 2 years before Meade and Celestron came out with their ACF and Edge optics. We used a RC to design our MFR-5 and results speaks for itself. Results were spectacular with all refractors tested on which included TeleVue Genesis and many other high end refractors. Maksutov optical design have produced some spectacular result as well with no optical aberration what so ever.

      Because the majority of Newtonian are F/5 or less, it is not practical to use a MFR-5 on a Newtonian type telescope. It just don't make sense at all. The MFR-3 was design for all Newtonian type telescopes in aperture of up to 32". We use a 16" F/4.5 to design the MFR-3 on a EQ mount way back then in 2003 -2004. Result again was very consistent lower F ratio with no observable optical aberration. Further improvement have been made on the MFR-3 in later years to incorporate further correction for parabolic curvature of Newtonian design. Lenses used to be hand grounded in our shop and hand made. Any one claiming a MFR-3 is just a "simple regular" focal reducer, have no idea of the work and designing that went through this design for Newtonian and other uses on a variety of telescopes where a "milder" reduction is needed. They surely been miss informed about the product and their optical design for 1/2" ccd video sensor.

      Same applies to the MFR-5. A lot of optical engineering went through the design of the MFR-5 and recently new lenses made in Germany with premium optical glass has been further enhanced.

      These focal reducers are design for 1/2 ccd work, mainly video ccd and nothing else. Designed and made right here in Ottawa after years of testing and testing thought, results speaks for themselves with a rpoduct especially design for video ccd work.

      We cannot guaranty the focal length of any specific telescopes as too many variants are present in any telescopes. Not all scopes are made the same way. Adjusting the MFR-5 and MFR-3 with a series of spacers will make a user achieve a focal length to make his or her image the best observed live.

      Rock M.






      --- In mallincam@yahoogroups.com, "dom7mak" <domokos543@...> wrote:
      >
      > Mark,
      >
      > The MFR-5 combinations that you tried yield 0.3-0.4x reduction factors. That may be too much for an f/7 refractor. Plus the MFR-5 is designed for spherical mirror f/10 SCT's. It may attempt to correct an aberration that your high class refactor doesn't have.
      >
      > MFR-3 with 10mm spacer produces a 0.65x reduction, which is more appropriate for an f/7 scope. Moreover the the MFR-3 is a straightforward focal reducer. It doesn't attempt to correct anything.
      >
      > --Dom
      >
      > --- In mallincam@yahoogroups.com, "mpetraglia@" <mpetraglia@> wrote:
      > >
      > >
      > > Rock,
      > >
      > > This evening I tried the MFR5 in the following combo's
      > >
      > > -MFR5 with 5m between lens cells
      > > -MFR5 with 10m between lens cells
      > > -MFR5 with 10m between camera and MFR5
      > > -MFR5 with 5m between camera and MFR5
      > > -MFR5 with 5m and 10m (15M) between camera and MFR5
      > >
      > > Still the MFR3 with 10m between camera and MFR3 produced the best results with pin point stars to the edges.
      > >
      > >
      > > --- In mallincam@yahoogroups.com, "MallinCam" <mallincam@> wrote:
      > > >
      > > > Marc
      > > >
      > > > Try the MFR-5 without any spacers. Try adding a 5 mm spacer between both element of the MFR-5. Works on some telescope. That is why the MFR-5 has so many combinations to use for specific telescope. You need to experiment.
      > > >
      > > > Rock M.
      > > >
      > > > --- In mallincam@yahoogroups.com, "mpetraglia@" <mpetraglia@> wrote:
      > > > >
      > > > > I did a test using the MFR5 and MFR3 along with both 5m and 10m spacer between camera and MFRx. I found the following
      > > > >
      > > > > -MFR5 I get coma and it's improved with the 10M between camera and MFR5 but still present
      > > > >
      > > > > -MFR3 with 10M works great. nice round start to the edge of field.
      > > > >
      > > > > Does anyone have any further knowledge or comments to share
      > > > >
      > > > > I'm a bit confused as I've read that I should be using the MFR5 but can;t seem to get rid of the coma
      > > > >
      > > > > Thanks
      > > > > Marc
      > > > >
      > > >
      > >
      >
    • MallinCam
      Dom, I am sorry to say that your assessment is incorrect when it comes to the MFR-5 and MFR-3. MFR-5 uses two totally different shaped lenses and sizes. First
      Message 2 of 20 , Jun 26, 2012
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        Dom,

        I am sorry to say that your assessment is incorrect when it comes to the MFR-5 and MFR-3. MFR-5 uses two totally different shaped lenses and sizes. First part is 25 mm the other rear section is 21 mm. That alone will have a huge effect on correction distance that must be well calculated for the 1/2" ccd sensor and their distance. That alone puts the MFR-5 in its own class regardless what others have put out. We don't just use "any" achromatic lenses. Our system is far too sensitive for that. They are shaped and cut to precision using lasers technologies.

        I am sorry to hear some have such opinion and assessment of such development for video ccd sensors. That, I must say, after all the years and tens of thousand of dollars invested in research to develop our MFR-3 and MFR-5, saddens me deeply. Next time I observe through my own system including a MFR-5, I will no longer look at stars the same way I used to.

        I am blown away on such opinions. Thank Goodness for freedom of speech, I respect your opinion, Dom.

        Rock .



        --- In mallincam@yahoogroups.com, "dom7mak" <domokos543@...> wrote:
        >
        > Hi All,
        >
        > I took apart a number of reducer/correctors that are specifically marketed for SCT's. Inluding two Meade/Celestron/Antares/Hirsch 6.3's and Baader's Alan Gee II. All of them consisted of two lenses with a spacer inbetween. Two achromats in the first case and two single lenses in the Alan Gee.
        >
        > From this I infer that this combination has the ability to produce an aberration, that is the opposite of what the SCT's create. Hence the corrector effect. (I am using the word ability because, of course, there is much more to an optical design than just putting two lenses and a spacer together.)
        >
        > The two-piece MFR-5 is something similar. Moreover, it is basically a kit. Placing spacers here and there the user can assemble a whole array of different optical systems with varying effects. This may also be part of the secret to its versatility.
        >
        > --Dom
        >
        > --- In mallincam@yahoogroups.com, "Woody Schlom" <woody@> wrote:
        > >
        > > Dom and Marc,
        > >
        > > I'm not sure all Dom's assumptions/assertions are correct.
        > >
        > > For example, I don't think the MFR-5 was "designed for spherical mirror
        > > f/10 SCT's" exclusively. That's one of the points Rock makes regarding
        > > the MFR-5 -- it's much more of a universal focal-reducer than one
        > > designed specifically for a single optical system. The MFR-3 on the
        > > other hand was specifically designed for fast focal-ratio Newtonians.
        > >
        > > And if you're thinking that the MFR-5 was designed specifically for
        > > scopes with a sharply curved focal plane -- instead of a flat focal
        > > plane such as you'd find in an astrograph -- then you might be mistaken
        > > again. Rock claims his MFR-5 works very well with RC design scopes --
        > > which usually have much flatter focus planes as well as the newer Edge
        > > HD and Meade ACF SCTs which supposedly have flatter field focus. Don't
        > > ask me optically or physically how this is possible because it really
        > > doesn't make sense to me. But those are the claims -- from both Rock
        > > and end-users.
        > >
        > > But Dom's suggestion that in the configurations Marc has tried, the
        > > MFR-5 is reducing the field too much for this particular scope -- that
        > > might be closer to the mark.
        > >
        > > I have successfully used a MFR-5 on a f/7 (f/6.8 actually) APO refractor
        > > (not flat field, just APO). So I don't think f/7 is particularly exotic
        > > or too "fast" for the MFR-5.
        > >
        > > Marc -- did you try just using the back part of the MFR-5 -- without the
        > > front part at all? Just using the back part results in much less
        > > focal-reduction -- if that's the problem here.
        > >
        > > Woody
        > >
        > >
        > > -----Original Message-----
        > > From: mallincam@yahoogroups.com [mailto:mallincam@yahoogroups.com] On
        > > Behalf Of dom7mak
        > > Sent: Monday, June 25, 2012 11:35 PM
        > > To: mallincam@yahoogroups.com
        > > Subject: [MallinCam] Re: MFR3 with TMB130SS
        > >
        > >
        > >
        > >
        > > Mark,
        > >
        > > The MFR-5 combinations that you tried yield 0.3-0.4x reduction factors.
        > > That may be too much for an f/7 refractor. Plus the MFR-5 is designed
        > > for spherical mirror f/10 SCT's. It may attempt to correct an aberration
        > > that your high class refactor doesn't have.
        > >
        > > MFR-3 with 10mm spacer produces a 0.65x reduction, which is more
        > > appropriate for an f/7 scope. Moreover the the MFR-3 is a
        > > straightforward focal reducer. It doesn't attempt to correct anything.
        > >
        > > --Dom
        > >
        > > --- In mallincam@yahoogroups.com <mailto:mallincam%40yahoogroups.com> ,
        > > "mpetraglia@" <mpetraglia@> wrote:
        > > >
        > > >
        > > > Rock,
        > > >
        > > > This evening I tried the MFR5 in the following combo's
        > > >
        > > > -MFR5 with 5m between lens cells
        > > > -MFR5 with 10m between lens cells
        > > > -MFR5 with 10m between camera and MFR5
        > > > -MFR5 with 5m between camera and MFR5
        > > > -MFR5 with 5m and 10m (15M) between camera and MFR5
        > > >
        > > > Still the MFR3 with 10m between camera and MFR3 produced the best
        > > results with pin point stars to the edges.
        > > >
        > > >
        > > > --- In mallincam@yahoogroups.com <mailto:mallincam%40yahoogroups.com>
        > > , "MallinCam" <mallincam@> wrote:
        > > > >
        > > > > Marc
        > > > >
        > > > > Try the MFR-5 without any spacers. Try adding a 5 mm spacer between
        > > both element of the MFR-5. Works on some telescope. That is why the
        > > MFR-5 has so many combinations to use for specific telescope. You need
        > > to experiment.
        > > > >
        > > > > Rock M.
        > > > >
        > > > > --- In mallincam@yahoogroups.com
        > > <mailto:mallincam%40yahoogroups.com> , "mpetraglia@" <mpetraglia@>
        > > wrote:
        > > > > >
        > > > > > I did a test using the MFR5 and MFR3 along with both 5m and 10m
        > > spacer between camera and MFRx. I found the following
        > > > > >
        > > > > > -MFR5 I get coma and it's improved with the 10M between camera and
        > > MFR5 but still present
        > > > > >
        > > > > > -MFR3 with 10M works great. nice round start to the edge of field.
        > > > > >
        > > > > > Does anyone have any further knowledge or comments to share
        > > > > >
        > > > > > I'm a bit confused as I've read that I should be using the MFR5
        > > but can;t seem to get rid of the coma
        > > > > >
        > > > > > Thanks
        > > > > > Marc
        > > > > >
        > > > >
        > > >
        > >
        > >
        > >
        > >
        > >
        > >
        > >
        > > [Non-text portions of this message have been removed]
        > >
        >
      • Howard
        Relax, Rock You set the record straight, again... Dom is better informed now Howard ... [Non-text portions of this message have been removed]
        Message 3 of 20 , Jun 26, 2012
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          Relax, Rock

          You set the record straight, again...

          Dom is better informed now

          Howard



          On 26 Jun 2012, at 21:11, "MallinCam" <mallincam@...> wrote:

          > Dom,
          >
          > I am sorry to say that your assessment is incorrect when it comes to the MFR-5 and MFR-3. MFR-5 uses two totally different shaped lenses and sizes. First part is 25 mm the other rear section is 21 mm. That alone will have a huge effect on correction distance that must be well calculated for the 1/2" ccd sensor and their distance. That alone puts the MFR-5 in its own class regardless what others have put out. We don't just use "any" achromatic lenses. Our system is far too sensitive for that. They are shaped and cut to precision using lasers technologies.
          >
          > I am sorry to hear some have such opinion and assessment of such development for video ccd sensors. That, I must say, after all the years and tens of thousand of dollars invested in research to develop our MFR-3 and MFR-5, saddens me deeply. Next time I observe through my own system including a MFR-5, I will no longer look at stars the same way I used to.
          >
          > I am blown away on such opinions. Thank Goodness for freedom of speech, I respect your opinion, Dom.
          >
          > Rock .
          >
          > --- In mallincam@yahoogroups.com, "dom7mak" <domokos543@...> wrote:
          > >
          > > Hi All,
          > >
          > > I took apart a number of reducer/correctors that are specifically marketed for SCT's. Inluding two Meade/Celestron/Antares/Hirsch 6.3's and Baader's Alan Gee II. All of them consisted of two lenses with a spacer inbetween. Two achromats in the first case and two single lenses in the Alan Gee.
          > >
          > > From this I infer that this combination has the ability to produce an aberration, that is the opposite of what the SCT's create. Hence the corrector effect. (I am using the word ability because, of course, there is much more to an optical design than just putting two lenses and a spacer together.)
          > >
          > > The two-piece MFR-5 is something similar. Moreover, it is basically a kit. Placing spacers here and there the user can assemble a whole array of different optical systems with varying effects. This may also be part of the secret to its versatility.
          > >
          > > --Dom
          > >
          > > --- In mallincam@yahoogroups.com, "Woody Schlom" <woody@> wrote:
          > > >
          > > > Dom and Marc,
          > > >
          > > > I'm not sure all Dom's assumptions/assertions are correct.
          > > >
          > > > For example, I don't think the MFR-5 was "designed for spherical mirror
          > > > f/10 SCT's" exclusively. That's one of the points Rock makes regarding
          > > > the MFR-5 -- it's much more of a universal focal-reducer than one
          > > > designed specifically for a single optical system. The MFR-3 on the
          > > > other hand was specifically designed for fast focal-ratio Newtonians.
          > > >
          > > > And if you're thinking that the MFR-5 was designed specifically for
          > > > scopes with a sharply curved focal plane -- instead of a flat focal
          > > > plane such as you'd find in an astrograph -- then you might be mistaken
          > > > again. Rock claims his MFR-5 works very well with RC design scopes --
          > > > which usually have much flatter focus planes as well as the newer Edge
          > > > HD and Meade ACF SCTs which supposedly have flatter field focus. Don't
          > > > ask me optically or physically how this is possible because it really
          > > > doesn't make sense to me. But those are the claims -- from both Rock
          > > > and end-users.
          > > >
          > > > But Dom's suggestion that in the configurations Marc has tried, the
          > > > MFR-5 is reducing the field too much for this particular scope -- that
          > > > might be closer to the mark.
          > > >
          > > > I have successfully used a MFR-5 on a f/7 (f/6.8 actually) APO refractor
          > > > (not flat field, just APO). So I don't think f/7 is particularly exotic
          > > > or too "fast" for the MFR-5.
          > > >
          > > > Marc -- did you try just using the back part of the MFR-5 -- without the
          > > > front part at all? Just using the back part results in much less
          > > > focal-reduction -- if that's the problem here.
          > > >
          > > > Woody
          > > >
          > > >
          > > > -----Original Message-----
          > > > From: mallincam@yahoogroups.com [mailto:mallincam@yahoogroups.com] On
          > > > Behalf Of dom7mak
          > > > Sent: Monday, June 25, 2012 11:35 PM
          > > > To: mallincam@yahoogroups.com
          > > > Subject: [MallinCam] Re: MFR3 with TMB130SS
          > > >
          > > >
          > > >
          > > >
          > > > Mark,
          > > >
          > > > The MFR-5 combinations that you tried yield 0.3-0.4x reduction factors.
          > > > That may be too much for an f/7 refractor. Plus the MFR-5 is designed
          > > > for spherical mirror f/10 SCT's. It may attempt to correct an aberration
          > > > that your high class refactor doesn't have.
          > > >
          > > > MFR-3 with 10mm spacer produces a 0.65x reduction, which is more
          > > > appropriate for an f/7 scope. Moreover the the MFR-3 is a
          > > > straightforward focal reducer. It doesn't attempt to correct anything.
          > > >
          > > > --Dom
          > > >
          > > > --- In mallincam@yahoogroups.com <mailto:mallincam%40yahoogroups.com> ,
          > > > "mpetraglia@" <mpetraglia@> wrote:
          > > > >
          > > > >
          > > > > Rock,
          > > > >
          > > > > This evening I tried the MFR5 in the following combo's
          > > > >
          > > > > -MFR5 with 5m between lens cells
          > > > > -MFR5 with 10m between lens cells
          > > > > -MFR5 with 10m between camera and MFR5
          > > > > -MFR5 with 5m between camera and MFR5
          > > > > -MFR5 with 5m and 10m (15M) between camera and MFR5
          > > > >
          > > > > Still the MFR3 with 10m between camera and MFR3 produced the best
          > > > results with pin point stars to the edges.
          > > > >
          > > > >
          > > > > --- In mallincam@yahoogroups.com <mailto:mallincam%40yahoogroups.com>
          > > > , "MallinCam" <mallincam@> wrote:
          > > > > >
          > > > > > Marc
          > > > > >
          > > > > > Try the MFR-5 without any spacers. Try adding a 5 mm spacer between
          > > > both element of the MFR-5. Works on some telescope. That is why the
          > > > MFR-5 has so many combinations to use for specific telescope. You need
          > > > to experiment.
          > > > > >
          > > > > > Rock M.
          > > > > >
          > > > > > --- In mallincam@yahoogroups.com
          > > > <mailto:mallincam%40yahoogroups.com> , "mpetraglia@" <mpetraglia@>
          > > > wrote:
          > > > > > >
          > > > > > > I did a test using the MFR5 and MFR3 along with both 5m and 10m
          > > > spacer between camera and MFRx. I found the following
          > > > > > >
          > > > > > > -MFR5 I get coma and it's improved with the 10M between camera and
          > > > MFR5 but still present
          > > > > > >
          > > > > > > -MFR3 with 10M works great. nice round start to the edge of field.
          > > > > > >
          > > > > > > Does anyone have any further knowledge or comments to share
          > > > > > >
          > > > > > > I'm a bit confused as I've read that I should be using the MFR5
          > > > but can;t seem to get rid of the coma
          > > > > > >
          > > > > > > Thanks
          > > > > > > Marc
          > > > > > >
          > > > > >
          > > > >
          > > >
          > > >
          > > >
          > > >
          > > >
          > > >
          > > >
          > > > [Non-text portions of this message have been removed]
          > > >
          > >
          >
          >
          >
          >
          >
          >
          >

          [Non-text portions of this message have been removed]
        • mpetraglia@rogers.com
          First, Off my apologies if this topic has caused some heated discussions. I asked the questions I asked first and for most being new to video astronomy and
          Message 4 of 20 , Jun 26, 2012
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            First,

            Off my apologies if this topic has caused some heated discussions.

            I asked the questions I asked first and for most being new to video astronomy and CCD's as a whole.

            Simply, I'm finding rounder pin point stars using the MFR3 w/10M spacer (between camera and MFR3)

            I'm trying to find out if I'm missing something or doing something wrong as from what I read I should be using the MFR-5

            Woody Thanks for the tip.. I will try using just the back cell of the MFR-5.

            I should also add that I'm using the camera directly in the back of the TMB130SS (no diagonal) and need to use a extention tube to get enough focus track.

            Thanks
            Marc

            --- In mallincam@yahoogroups.com, "MallinCam" <mallincam@...> wrote:
            >
            > Dom,
            >
            > I am sorry to say that your assessment is incorrect when it comes to the MFR-5 and MFR-3. MFR-5 uses two totally different shaped lenses and sizes. First part is 25 mm the other rear section is 21 mm. That alone will have a huge effect on correction distance that must be well calculated for the 1/2" ccd sensor and their distance. That alone puts the MFR-5 in its own class regardless what others have put out. We don't just use "any" achromatic lenses. Our system is far too sensitive for that. They are shaped and cut to precision using lasers technologies.
            >
            > I am sorry to hear some have such opinion and assessment of such development for video ccd sensors. That, I must say, after all the years and tens of thousand of dollars invested in research to develop our MFR-3 and MFR-5, saddens me deeply. Next time I observe through my own system including a MFR-5, I will no longer look at stars the same way I used to.
            >
            > I am blown away on such opinions. Thank Goodness for freedom of speech, I respect your opinion, Dom.
            >
            > Rock .
            >
            >
            >
            > --- In mallincam@yahoogroups.com, "dom7mak" <domokos543@> wrote:
            > >
            > > Hi All,
            > >
            > > I took apart a number of reducer/correctors that are specifically marketed for SCT's. Inluding two Meade/Celestron/Antares/Hirsch 6.3's and Baader's Alan Gee II. All of them consisted of two lenses with a spacer inbetween. Two achromats in the first case and two single lenses in the Alan Gee.
            > >
            > > From this I infer that this combination has the ability to produce an aberration, that is the opposite of what the SCT's create. Hence the corrector effect. (I am using the word ability because, of course, there is much more to an optical design than just putting two lenses and a spacer together.)
            > >
            > > The two-piece MFR-5 is something similar. Moreover, it is basically a kit. Placing spacers here and there the user can assemble a whole array of different optical systems with varying effects. This may also be part of the secret to its versatility.
            > >
            > > --Dom
            > >
            > > --- In mallincam@yahoogroups.com, "Woody Schlom" <woody@> wrote:
            > > >
            > > > Dom and Marc,
            > > >
            > > > I'm not sure all Dom's assumptions/assertions are correct.
            > > >
            > > > For example, I don't think the MFR-5 was "designed for spherical mirror
            > > > f/10 SCT's" exclusively. That's one of the points Rock makes regarding
            > > > the MFR-5 -- it's much more of a universal focal-reducer than one
            > > > designed specifically for a single optical system. The MFR-3 on the
            > > > other hand was specifically designed for fast focal-ratio Newtonians.
            > > >
            > > > And if you're thinking that the MFR-5 was designed specifically for
            > > > scopes with a sharply curved focal plane -- instead of a flat focal
            > > > plane such as you'd find in an astrograph -- then you might be mistaken
            > > > again. Rock claims his MFR-5 works very well with RC design scopes --
            > > > which usually have much flatter focus planes as well as the newer Edge
            > > > HD and Meade ACF SCTs which supposedly have flatter field focus. Don't
            > > > ask me optically or physically how this is possible because it really
            > > > doesn't make sense to me. But those are the claims -- from both Rock
            > > > and end-users.
            > > >
            > > > But Dom's suggestion that in the configurations Marc has tried, the
            > > > MFR-5 is reducing the field too much for this particular scope -- that
            > > > might be closer to the mark.
            > > >
            > > > I have successfully used a MFR-5 on a f/7 (f/6.8 actually) APO refractor
            > > > (not flat field, just APO). So I don't think f/7 is particularly exotic
            > > > or too "fast" for the MFR-5.
            > > >
            > > > Marc -- did you try just using the back part of the MFR-5 -- without the
            > > > front part at all? Just using the back part results in much less
            > > > focal-reduction -- if that's the problem here.
            > > >
            > > > Woody
            > > >
            > > >
            > > > -----Original Message-----
            > > > From: mallincam@yahoogroups.com [mailto:mallincam@yahoogroups.com] On
            > > > Behalf Of dom7mak
            > > > Sent: Monday, June 25, 2012 11:35 PM
            > > > To: mallincam@yahoogroups.com
            > > > Subject: [MallinCam] Re: MFR3 with TMB130SS
            > > >
            > > >
            > > >
            > > >
            > > > Mark,
            > > >
            > > > The MFR-5 combinations that you tried yield 0.3-0.4x reduction factors.
            > > > That may be too much for an f/7 refractor. Plus the MFR-5 is designed
            > > > for spherical mirror f/10 SCT's. It may attempt to correct an aberration
            > > > that your high class refactor doesn't have.
            > > >
            > > > MFR-3 with 10mm spacer produces a 0.65x reduction, which is more
            > > > appropriate for an f/7 scope. Moreover the the MFR-3 is a
            > > > straightforward focal reducer. It doesn't attempt to correct anything.
            > > >
            > > > --Dom
            > > >
            > > > --- In mallincam@yahoogroups.com <mailto:mallincam%40yahoogroups.com> ,
            > > > "mpetraglia@" <mpetraglia@> wrote:
            > > > >
            > > > >
            > > > > Rock,
            > > > >
            > > > > This evening I tried the MFR5 in the following combo's
            > > > >
            > > > > -MFR5 with 5m between lens cells
            > > > > -MFR5 with 10m between lens cells
            > > > > -MFR5 with 10m between camera and MFR5
            > > > > -MFR5 with 5m between camera and MFR5
            > > > > -MFR5 with 5m and 10m (15M) between camera and MFR5
            > > > >
            > > > > Still the MFR3 with 10m between camera and MFR3 produced the best
            > > > results with pin point stars to the edges.
            > > > >
            > > > >
            > > > > --- In mallincam@yahoogroups.com <mailto:mallincam%40yahoogroups.com>
            > > > , "MallinCam" <mallincam@> wrote:
            > > > > >
            > > > > > Marc
            > > > > >
            > > > > > Try the MFR-5 without any spacers. Try adding a 5 mm spacer between
            > > > both element of the MFR-5. Works on some telescope. That is why the
            > > > MFR-5 has so many combinations to use for specific telescope. You need
            > > > to experiment.
            > > > > >
            > > > > > Rock M.
            > > > > >
            > > > > > --- In mallincam@yahoogroups.com
            > > > <mailto:mallincam%40yahoogroups.com> , "mpetraglia@" <mpetraglia@>
            > > > wrote:
            > > > > > >
            > > > > > > I did a test using the MFR5 and MFR3 along with both 5m and 10m
            > > > spacer between camera and MFRx. I found the following
            > > > > > >
            > > > > > > -MFR5 I get coma and it's improved with the 10M between camera and
            > > > MFR5 but still present
            > > > > > >
            > > > > > > -MFR3 with 10M works great. nice round start to the edge of field.
            > > > > > >
            > > > > > > Does anyone have any further knowledge or comments to share
            > > > > > >
            > > > > > > I'm a bit confused as I've read that I should be using the MFR5
            > > > but can;t seem to get rid of the coma
            > > > > > >
            > > > > > > Thanks
            > > > > > > Marc
            > > > > > >
            > > > > >
            > > > >
            > > >
            > > >
            > > >
            > > >
            > > >
            > > >
            > > >
            > > > [Non-text portions of this message have been removed]
            > > >
            > >
            >
          • John Hilliard
            Hey Marc, I have learned that what works for one does not necessarily make another happy...same/similar camera/equipment/monitor/cable/power supply/etc...does
            Message 5 of 20 , Jun 26, 2012
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              Hey Marc,

              I have learned that what works for one does not necessarily make another happy...same/similar camera/equipment/monitor/cable/power supply/etc...does not matter.


              We used our VSS w/ MFR-5 on a TV-85 and life was pretty good when using it with a diagonal. Without a diagonal we could not reach focus and did not have an MFR-3 to try, and at the time we were not aware that we could split the 5 and just use the back half. The scope is gone now.

              The bottom line:
              If you and your system are happy...life is good so ENJOY!


              John
              ----- Original Message -----
              From: mpetraglia@...
              To: mallincam@yahoogroups.com
              Sent: Tuesday, June 26, 2012 4:49 PM
              Subject: [MallinCam] Re: MFR3 with TMB130SS



              First,

              Off my apologies if this topic has caused some heated discussions.

              I asked the questions I asked first and for most being new to video astronomy and CCD's as a whole.

              Simply, I'm finding rounder pin point stars using the MFR3 w/10M spacer (between camera and MFR3)

              I'm trying to find out if I'm missing something or doing something wrong as from what I read I should be using the MFR-5

              Woody Thanks for the tip.. I will try using just the back cell of the MFR-5.

              I should also add that I'm using the camera directly in the back of the TMB130SS (no diagonal) and need to use a extention tube to get enough focus track.

              Thanks
              Marc


              [Non-text portions of this message have been removed]
            • MallinCam
              Hi Marc, No apology needed. Questions are always welcome on the group. It help everyone especially new comers. Keep in mind that sometime same question were
              Message 6 of 20 , Jun 26, 2012
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                Hi Marc,

                No apology needed. Questions are always welcome on the group. It help everyone especially new comers.

                Keep in mind that sometime same question were asked before and beaten to death on same topics and many times answers is already available through a quick search of topics. So, sometime, answers may sound direct. I am a very direct person and get to the point. Tones in e mail are usually easily detected which make e mail one of the worst way to communicate and express proper ideas or replies.


                It is I who apologize.

                Rock M.

                --- In mallincam@yahoogroups.com, "mpetraglia@..." <mpetraglia@...> wrote:
                >
                >
                > First,
                >
                > Off my apologies if this topic has caused some heated discussions.
                >
                > I asked the questions I asked first and for most being new to video astronomy and CCD's as a whole.
                >
                > Simply, I'm finding rounder pin point stars using the MFR3 w/10M spacer (between camera and MFR3)
                >
                > I'm trying to find out if I'm missing something or doing something wrong as from what I read I should be using the MFR-5
                >
                > Woody Thanks for the tip.. I will try using just the back cell of the MFR-5.
                >
                > I should also add that I'm using the camera directly in the back of the TMB130SS (no diagonal) and need to use a extention tube to get enough focus track.
                >
                > Thanks
                > Marc
                >
                > --- In mallincam@yahoogroups.com, "MallinCam" <mallincam@> wrote:
                > >
                > > Dom,
                > >
                > > I am sorry to say that your assessment is incorrect when it comes to the MFR-5 and MFR-3. MFR-5 uses two totally different shaped lenses and sizes. First part is 25 mm the other rear section is 21 mm. That alone will have a huge effect on correction distance that must be well calculated for the 1/2" ccd sensor and their distance. That alone puts the MFR-5 in its own class regardless what others have put out. We don't just use "any" achromatic lenses. Our system is far too sensitive for that. They are shaped and cut to precision using lasers technologies.
                > >
                > > I am sorry to hear some have such opinion and assessment of such development for video ccd sensors. That, I must say, after all the years and tens of thousand of dollars invested in research to develop our MFR-3 and MFR-5, saddens me deeply. Next time I observe through my own system including a MFR-5, I will no longer look at stars the same way I used to.
                > >
                > > I am blown away on such opinions. Thank Goodness for freedom of speech, I respect your opinion, Dom.
                > >
                > > Rock .
                > >
                > >
                > >
                > > --- In mallincam@yahoogroups.com, "dom7mak" <domokos543@> wrote:
                > > >
                > > > Hi All,
                > > >
                > > > I took apart a number of reducer/correctors that are specifically marketed for SCT's. Inluding two Meade/Celestron/Antares/Hirsch 6.3's and Baader's Alan Gee II. All of them consisted of two lenses with a spacer inbetween. Two achromats in the first case and two single lenses in the Alan Gee.
                > > >
                > > > From this I infer that this combination has the ability to produce an aberration, that is the opposite of what the SCT's create. Hence the corrector effect. (I am using the word ability because, of course, there is much more to an optical design than just putting two lenses and a spacer together.)
                > > >
                > > > The two-piece MFR-5 is something similar. Moreover, it is basically a kit. Placing spacers here and there the user can assemble a whole array of different optical systems with varying effects. This may also be part of the secret to its versatility.
                > > >
                > > > --Dom
                > > >
                > > > --- In mallincam@yahoogroups.com, "Woody Schlom" <woody@> wrote:
                > > > >
                > > > > Dom and Marc,
                > > > >
                > > > > I'm not sure all Dom's assumptions/assertions are correct.
                > > > >
                > > > > For example, I don't think the MFR-5 was "designed for spherical mirror
                > > > > f/10 SCT's" exclusively. That's one of the points Rock makes regarding
                > > > > the MFR-5 -- it's much more of a universal focal-reducer than one
                > > > > designed specifically for a single optical system. The MFR-3 on the
                > > > > other hand was specifically designed for fast focal-ratio Newtonians.
                > > > >
                > > > > And if you're thinking that the MFR-5 was designed specifically for
                > > > > scopes with a sharply curved focal plane -- instead of a flat focal
                > > > > plane such as you'd find in an astrograph -- then you might be mistaken
                > > > > again. Rock claims his MFR-5 works very well with RC design scopes --
                > > > > which usually have much flatter focus planes as well as the newer Edge
                > > > > HD and Meade ACF SCTs which supposedly have flatter field focus. Don't
                > > > > ask me optically or physically how this is possible because it really
                > > > > doesn't make sense to me. But those are the claims -- from both Rock
                > > > > and end-users.
                > > > >
                > > > > But Dom's suggestion that in the configurations Marc has tried, the
                > > > > MFR-5 is reducing the field too much for this particular scope -- that
                > > > > might be closer to the mark.
                > > > >
                > > > > I have successfully used a MFR-5 on a f/7 (f/6.8 actually) APO refractor
                > > > > (not flat field, just APO). So I don't think f/7 is particularly exotic
                > > > > or too "fast" for the MFR-5.
                > > > >
                > > > > Marc -- did you try just using the back part of the MFR-5 -- without the
                > > > > front part at all? Just using the back part results in much less
                > > > > focal-reduction -- if that's the problem here.
                > > > >
                > > > > Woody
                > > > >
                > > > >
                > > > > -----Original Message-----
                > > > > From: mallincam@yahoogroups.com [mailto:mallincam@yahoogroups.com] On
                > > > > Behalf Of dom7mak
                > > > > Sent: Monday, June 25, 2012 11:35 PM
                > > > > To: mallincam@yahoogroups.com
                > > > > Subject: [MallinCam] Re: MFR3 with TMB130SS
                > > > >
                > > > >
                > > > >
                > > > >
                > > > > Mark,
                > > > >
                > > > > The MFR-5 combinations that you tried yield 0.3-0.4x reduction factors.
                > > > > That may be too much for an f/7 refractor. Plus the MFR-5 is designed
                > > > > for spherical mirror f/10 SCT's. It may attempt to correct an aberration
                > > > > that your high class refactor doesn't have.
                > > > >
                > > > > MFR-3 with 10mm spacer produces a 0.65x reduction, which is more
                > > > > appropriate for an f/7 scope. Moreover the the MFR-3 is a
                > > > > straightforward focal reducer. It doesn't attempt to correct anything.
                > > > >
                > > > > --Dom
                > > > >
                > > > > --- In mallincam@yahoogroups.com <mailto:mallincam%40yahoogroups.com> ,
                > > > > "mpetraglia@" <mpetraglia@> wrote:
                > > > > >
                > > > > >
                > > > > > Rock,
                > > > > >
                > > > > > This evening I tried the MFR5 in the following combo's
                > > > > >
                > > > > > -MFR5 with 5m between lens cells
                > > > > > -MFR5 with 10m between lens cells
                > > > > > -MFR5 with 10m between camera and MFR5
                > > > > > -MFR5 with 5m between camera and MFR5
                > > > > > -MFR5 with 5m and 10m (15M) between camera and MFR5
                > > > > >
                > > > > > Still the MFR3 with 10m between camera and MFR3 produced the best
                > > > > results with pin point stars to the edges.
                > > > > >
                > > > > >
                > > > > > --- In mallincam@yahoogroups.com <mailto:mallincam%40yahoogroups.com>
                > > > > , "MallinCam" <mallincam@> wrote:
                > > > > > >
                > > > > > > Marc
                > > > > > >
                > > > > > > Try the MFR-5 without any spacers. Try adding a 5 mm spacer between
                > > > > both element of the MFR-5. Works on some telescope. That is why the
                > > > > MFR-5 has so many combinations to use for specific telescope. You need
                > > > > to experiment.
                > > > > > >
                > > > > > > Rock M.
                > > > > > >
                > > > > > > --- In mallincam@yahoogroups.com
                > > > > <mailto:mallincam%40yahoogroups.com> , "mpetraglia@" <mpetraglia@>
                > > > > wrote:
                > > > > > > >
                > > > > > > > I did a test using the MFR5 and MFR3 along with both 5m and 10m
                > > > > spacer between camera and MFRx. I found the following
                > > > > > > >
                > > > > > > > -MFR5 I get coma and it's improved with the 10M between camera and
                > > > > MFR5 but still present
                > > > > > > >
                > > > > > > > -MFR3 with 10M works great. nice round start to the edge of field.
                > > > > > > >
                > > > > > > > Does anyone have any further knowledge or comments to share
                > > > > > > >
                > > > > > > > I'm a bit confused as I've read that I should be using the MFR5
                > > > > but can;t seem to get rid of the coma
                > > > > > > >
                > > > > > > > Thanks
                > > > > > > > Marc
                > > > > > > >
                > > > > > >
                > > > > >
                > > > >
                > > > >
                > > > >
                > > > >
                > > > >
                > > > >
                > > > >
                > > > > [Non-text portions of this message have been removed]
                > > > >
                > > >
                > >
                >
              • mpetraglia@rogers.com
                Thanks Rock, I ll keep playing, at present I ll use the MFR3/10m spacer combo as it s preforming very well.
                Message 7 of 20 , Jun 27, 2012
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                  Thanks Rock,

                  I'll keep playing, at present I'll use the MFR3/10m spacer combo as it's preforming very well.

                  --- In mallincam@yahoogroups.com, "MallinCam" <mallincam@...> wrote:
                  >
                  > Hi Marc,
                  >
                  > No apology needed. Questions are always welcome on the group. It help everyone especially new comers.
                  >
                  > Keep in mind that sometime same question were asked before and beaten to death on same topics and many times answers is already available through a quick search of topics. So, sometime, answers may sound direct. I am a very direct person and get to the point. Tones in e mail are usually easily detected which make e mail one of the worst way to communicate and express proper ideas or replies.
                  >
                  >
                  > It is I who apologize.
                  >
                  > Rock M.
                  >
                  > --- In mallincam@yahoogroups.com, "mpetraglia@" <mpetraglia@> wrote:
                  > >
                  > >
                  > > First,
                  > >
                  > > Off my apologies if this topic has caused some heated discussions.
                  > >
                  > > I asked the questions I asked first and for most being new to video astronomy and CCD's as a whole.
                  > >
                  > > Simply, I'm finding rounder pin point stars using the MFR3 w/10M spacer (between camera and MFR3)
                  > >
                  > > I'm trying to find out if I'm missing something or doing something wrong as from what I read I should be using the MFR-5
                  > >
                  > > Woody Thanks for the tip.. I will try using just the back cell of the MFR-5.
                  > >
                  > > I should also add that I'm using the camera directly in the back of the TMB130SS (no diagonal) and need to use a extention tube to get enough focus track.
                  > >
                  > > Thanks
                  > > Marc
                  > >
                  > > --- In mallincam@yahoogroups.com, "MallinCam" <mallincam@> wrote:
                  > > >
                  > > > Dom,
                  > > >
                  > > > I am sorry to say that your assessment is incorrect when it comes to the MFR-5 and MFR-3. MFR-5 uses two totally different shaped lenses and sizes. First part is 25 mm the other rear section is 21 mm. That alone will have a huge effect on correction distance that must be well calculated for the 1/2" ccd sensor and their distance. That alone puts the MFR-5 in its own class regardless what others have put out. We don't just use "any" achromatic lenses. Our system is far too sensitive for that. They are shaped and cut to precision using lasers technologies.
                  > > >
                  > > > I am sorry to hear some have such opinion and assessment of such development for video ccd sensors. That, I must say, after all the years and tens of thousand of dollars invested in research to develop our MFR-3 and MFR-5, saddens me deeply. Next time I observe through my own system including a MFR-5, I will no longer look at stars the same way I used to.
                  > > >
                  > > > I am blown away on such opinions. Thank Goodness for freedom of speech, I respect your opinion, Dom.
                  > > >
                  > > > Rock .
                  > > >
                  > > >
                  > > >
                  > > > --- In mallincam@yahoogroups.com, "dom7mak" <domokos543@> wrote:
                  > > > >
                  > > > > Hi All,
                  > > > >
                  > > > > I took apart a number of reducer/correctors that are specifically marketed for SCT's. Inluding two Meade/Celestron/Antares/Hirsch 6.3's and Baader's Alan Gee II. All of them consisted of two lenses with a spacer inbetween. Two achromats in the first case and two single lenses in the Alan Gee.
                  > > > >
                  > > > > From this I infer that this combination has the ability to produce an aberration, that is the opposite of what the SCT's create. Hence the corrector effect. (I am using the word ability because, of course, there is much more to an optical design than just putting two lenses and a spacer together.)
                  > > > >
                  > > > > The two-piece MFR-5 is something similar. Moreover, it is basically a kit. Placing spacers here and there the user can assemble a whole array of different optical systems with varying effects. This may also be part of the secret to its versatility.
                  > > > >
                  > > > > --Dom
                  > > > >
                  > > > > --- In mallincam@yahoogroups.com, "Woody Schlom" <woody@> wrote:
                  > > > > >
                  > > > > > Dom and Marc,
                  > > > > >
                  > > > > > I'm not sure all Dom's assumptions/assertions are correct.
                  > > > > >
                  > > > > > For example, I don't think the MFR-5 was "designed for spherical mirror
                  > > > > > f/10 SCT's" exclusively. That's one of the points Rock makes regarding
                  > > > > > the MFR-5 -- it's much more of a universal focal-reducer than one
                  > > > > > designed specifically for a single optical system. The MFR-3 on the
                  > > > > > other hand was specifically designed for fast focal-ratio Newtonians.
                  > > > > >
                  > > > > > And if you're thinking that the MFR-5 was designed specifically for
                  > > > > > scopes with a sharply curved focal plane -- instead of a flat focal
                  > > > > > plane such as you'd find in an astrograph -- then you might be mistaken
                  > > > > > again. Rock claims his MFR-5 works very well with RC design scopes --
                  > > > > > which usually have much flatter focus planes as well as the newer Edge
                  > > > > > HD and Meade ACF SCTs which supposedly have flatter field focus. Don't
                  > > > > > ask me optically or physically how this is possible because it really
                  > > > > > doesn't make sense to me. But those are the claims -- from both Rock
                  > > > > > and end-users.
                  > > > > >
                  > > > > > But Dom's suggestion that in the configurations Marc has tried, the
                  > > > > > MFR-5 is reducing the field too much for this particular scope -- that
                  > > > > > might be closer to the mark.
                  > > > > >
                  > > > > > I have successfully used a MFR-5 on a f/7 (f/6.8 actually) APO refractor
                  > > > > > (not flat field, just APO). So I don't think f/7 is particularly exotic
                  > > > > > or too "fast" for the MFR-5.
                  > > > > >
                  > > > > > Marc -- did you try just using the back part of the MFR-5 -- without the
                  > > > > > front part at all? Just using the back part results in much less
                  > > > > > focal-reduction -- if that's the problem here.
                  > > > > >
                  > > > > > Woody
                  > > > > >
                  > > > > >
                  > > > > > -----Original Message-----
                  > > > > > From: mallincam@yahoogroups.com [mailto:mallincam@yahoogroups.com] On
                  > > > > > Behalf Of dom7mak
                  > > > > > Sent: Monday, June 25, 2012 11:35 PM
                  > > > > > To: mallincam@yahoogroups.com
                  > > > > > Subject: [MallinCam] Re: MFR3 with TMB130SS
                  > > > > >
                  > > > > >
                  > > > > >
                  > > > > >
                  > > > > > Mark,
                  > > > > >
                  > > > > > The MFR-5 combinations that you tried yield 0.3-0.4x reduction factors.
                  > > > > > That may be too much for an f/7 refractor. Plus the MFR-5 is designed
                  > > > > > for spherical mirror f/10 SCT's. It may attempt to correct an aberration
                  > > > > > that your high class refactor doesn't have.
                  > > > > >
                  > > > > > MFR-3 with 10mm spacer produces a 0.65x reduction, which is more
                  > > > > > appropriate for an f/7 scope. Moreover the the MFR-3 is a
                  > > > > > straightforward focal reducer. It doesn't attempt to correct anything.
                  > > > > >
                  > > > > > --Dom
                  > > > > >
                  > > > > > --- In mallincam@yahoogroups.com <mailto:mallincam%40yahoogroups.com> ,
                  > > > > > "mpetraglia@" <mpetraglia@> wrote:
                  > > > > > >
                  > > > > > >
                  > > > > > > Rock,
                  > > > > > >
                  > > > > > > This evening I tried the MFR5 in the following combo's
                  > > > > > >
                  > > > > > > -MFR5 with 5m between lens cells
                  > > > > > > -MFR5 with 10m between lens cells
                  > > > > > > -MFR5 with 10m between camera and MFR5
                  > > > > > > -MFR5 with 5m between camera and MFR5
                  > > > > > > -MFR5 with 5m and 10m (15M) between camera and MFR5
                  > > > > > >
                  > > > > > > Still the MFR3 with 10m between camera and MFR3 produced the best
                  > > > > > results with pin point stars to the edges.
                  > > > > > >
                  > > > > > >
                  > > > > > > --- In mallincam@yahoogroups.com <mailto:mallincam%40yahoogroups.com>
                  > > > > > , "MallinCam" <mallincam@> wrote:
                  > > > > > > >
                  > > > > > > > Marc
                  > > > > > > >
                  > > > > > > > Try the MFR-5 without any spacers. Try adding a 5 mm spacer between
                  > > > > > both element of the MFR-5. Works on some telescope. That is why the
                  > > > > > MFR-5 has so many combinations to use for specific telescope. You need
                  > > > > > to experiment.
                  > > > > > > >
                  > > > > > > > Rock M.
                  > > > > > > >
                  > > > > > > > --- In mallincam@yahoogroups.com
                  > > > > > <mailto:mallincam%40yahoogroups.com> , "mpetraglia@" <mpetraglia@>
                  > > > > > wrote:
                  > > > > > > > >
                  > > > > > > > > I did a test using the MFR5 and MFR3 along with both 5m and 10m
                  > > > > > spacer between camera and MFRx. I found the following
                  > > > > > > > >
                  > > > > > > > > -MFR5 I get coma and it's improved with the 10M between camera and
                  > > > > > MFR5 but still present
                  > > > > > > > >
                  > > > > > > > > -MFR3 with 10M works great. nice round start to the edge of field.
                  > > > > > > > >
                  > > > > > > > > Does anyone have any further knowledge or comments to share
                  > > > > > > > >
                  > > > > > > > > I'm a bit confused as I've read that I should be using the MFR5
                  > > > > > but can;t seem to get rid of the coma
                  > > > > > > > >
                  > > > > > > > > Thanks
                  > > > > > > > > Marc
                  > > > > > > > >
                  > > > > > > >
                  > > > > > >
                  > > > > >
                  > > > > >
                  > > > > >
                  > > > > >
                  > > > > >
                  > > > > >
                  > > > > >
                  > > > > > [Non-text portions of this message have been removed]
                  > > > > >
                  > > > >
                  > > >
                  > >
                  >
                • glennledrew
                  Rock, You re too hard on your MFR-5! Doesn t work so well on Newtonians, you say? I beg to differ! I spent a full night with my VSS+ and MFR-5 (no additional
                  Message 8 of 20 , Sep 6, 2012
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                    Rock,
                    You're too hard on your MFR-5! Doesn't work so well on Newtonians, you say? I beg to differ! I spent a full night with my VSS+ and MFR-5 (no additional spacers) attached to a friend's Skywatcher 12" f/4.9 GoTo dob, and got very nice results. The working f/ratio was about f/2.45. In order to achieve focus, the handy collapsible struts were pushed down about 1.5" and set with spacers. The only problem at times was some small amount of tracking irregularities, not aberrations introduced by the reducer.

                    So... The MFR-5--with no additional spacers at any rate--does work rather well with ~f/5 Newtonians if the focus can be achieved. Perhaps it's because of the more common difficulty of getting to focus due to insufficient in-travel that you point out the incompatibity with Newts. It sure is not an optical incompatibility!

                    Therefore, if one really desires to employ the MFR-5 on a Newtonian (around f/5, anyway) it will work if the primary-to-secondary mirror spacing can be reduced sufficiently.

                    Glenn LeDrew
                    Ottawa

                    --- In mallincam@yahoogroups.com, "MallinCam" <mallincam@...> wrote:
                    >
                    > Dom and all,
                    >
                    > We have covered this before several times on this list in past post. So, I';ll sound like an old broken record again. (i don't mind)
                    >
                    > The MFR-5 was design with two cells of two lenses each working together to achieve a low F/ratio from ANY telescope except a Newtonian type optic to deliver a lower F ratio. First set of lens (front part) is a 0.5.5X reduction and seconds is a CCD CORRECTOR field Flatner made FOR CCD of 1/2" in size only or 0.8X. The amount of reduction can vary from F/2.8 all the way to F/4.5 depending on optics used on. as tested on a optical bench and in the field.
                    >
                    > Using a series of spacers where greater distance will change this reduction can be pin point for optimal position between the ccd sensor and MFR-5 to deliver a specific final F ratio.
                    >
                    >
                    > It was mainly design for people who wanted to use a focal reducer with a diagonal to clear the way of the camera when used on a SCT in ALT-AZ just like my own SCT. But, the MFR-5 can be used as well at prime focus through a rear cell adapter of a SCT.
                    >
                    > Distance between smaller MFR-5 cell and ccd sensor will dictate the amount of vignetting, amount of uncorrected star field. The MFR-5 picks up what you feed it. If optics are of not "normal range", expect some artifact which needs to be corrected by removing all spacers from the MFR-5. Infrared can also play havoc on final reduction on some refractors and curvature of optics as well will result in artifact. Less reduction is then desired.
                    >
                    > MallinCam developed the MFR-5 2 years before Meade and Celestron came out with their ACF and Edge optics. We used a RC to design our MFR-5 and results speaks for itself. Results were spectacular with all refractors tested on which included TeleVue Genesis and many other high end refractors. Maksutov optical design have produced some spectacular result as well with no optical aberration what so ever.
                    >
                    > Because the majority of Newtonian are F/5 or less, it is not practical to use a MFR-5 on a Newtonian type telescope. It just don't make sense at all. The MFR-3 was design for all Newtonian type telescopes in aperture of up to 32". We use a 16" F/4.5 to design the MFR-3 on a EQ mount way back then in 2003 -2004. Result again was very consistent lower F ratio with no observable optical aberration. Further improvement have been made on the MFR-3 in later years to incorporate further correction for parabolic curvature of Newtonian design. Lenses used to be hand grounded in our shop and hand made. Any one claiming a MFR-3 is just a "simple regular" focal reducer, have no idea of the work and designing that went through this design for Newtonian and other uses on a variety of telescopes where a "milder" reduction is needed. They surely been miss informed about the product and their optical design for 1/2" ccd video sensor.
                    >
                    > Same applies to the MFR-5. A lot of optical engineering went through the design of the MFR-5 and recently new lenses made in Germany with premium optical glass has been further enhanced.
                    >
                    > These focal reducers are design for 1/2 ccd work, mainly video ccd and nothing else. Designed and made right here in Ottawa after years of testing and testing thought, results speaks for themselves with a rpoduct especially design for video ccd work.
                    >
                    > We cannot guaranty the focal length of any specific telescopes as too many variants are present in any telescopes. Not all scopes are made the same way. Adjusting the MFR-5 and MFR-3 with a series of spacers will make a user achieve a focal length to make his or her image the best observed live.
                    >
                    > Rock M.
                    >
                    >
                    >
                    >
                    >
                    >
                    > --- In mallincam@yahoogroups.com, "dom7mak" <domokos543@> wrote:
                    > >
                    > > Mark,
                    > >
                    > > The MFR-5 combinations that you tried yield 0.3-0.4x reduction factors. That may be too much for an f/7 refractor. Plus the MFR-5 is designed for spherical mirror f/10 SCT's. It may attempt to correct an aberration that your high class refactor doesn't have.
                    > >
                    > > MFR-3 with 10mm spacer produces a 0.65x reduction, which is more appropriate for an f/7 scope. Moreover the the MFR-3 is a straightforward focal reducer. It doesn't attempt to correct anything.
                    > >
                    > > --Dom
                    > >
                    > > --- In mallincam@yahoogroups.com, "mpetraglia@" <mpetraglia@> wrote:
                    > > >
                    > > >
                    > > > Rock,
                    > > >
                    > > > This evening I tried the MFR5 in the following combo's
                    > > >
                    > > > -MFR5 with 5m between lens cells
                    > > > -MFR5 with 10m between lens cells
                    > > > -MFR5 with 10m between camera and MFR5
                    > > > -MFR5 with 5m between camera and MFR5
                    > > > -MFR5 with 5m and 10m (15M) between camera and MFR5
                    > > >
                    > > > Still the MFR3 with 10m between camera and MFR3 produced the best results with pin point stars to the edges.
                    > > >
                    > > >
                    > > > --- In mallincam@yahoogroups.com, "MallinCam" <mallincam@> wrote:
                    > > > >
                    > > > > Marc
                    > > > >
                    > > > > Try the MFR-5 without any spacers. Try adding a 5 mm spacer between both element of the MFR-5. Works on some telescope. That is why the MFR-5 has so many combinations to use for specific telescope. You need to experiment.
                    > > > >
                    > > > > Rock M.
                    > > > >
                    > > > > --- In mallincam@yahoogroups.com, "mpetraglia@" <mpetraglia@> wrote:
                    > > > > >
                    > > > > > I did a test using the MFR5 and MFR3 along with both 5m and 10m spacer between camera and MFRx. I found the following
                    > > > > >
                    > > > > > -MFR5 I get coma and it's improved with the 10M between camera and MFR5 but still present
                    > > > > >
                    > > > > > -MFR3 with 10M works great. nice round start to the edge of field.
                    > > > > >
                    > > > > > Does anyone have any further knowledge or comments to share
                    > > > > >
                    > > > > > I'm a bit confused as I've read that I should be using the MFR5 but can;t seem to get rid of the coma
                    > > > > >
                    > > > > > Thanks
                    > > > > > Marc
                    > > > > >
                    > > > >
                    > > >
                    > >
                    >
                  • glennledrew
                    I should add that on my little 80mm f/5 achromat, the MFR-5 works well. But I have to set the focus very carefully, observing what s happening at the field
                    Message 9 of 20 , Sep 6, 2012
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                      I should add that on my little 80mm f/5 achromat, the MFR-5 works well. But I have to set the focus very carefully, observing what's happening at the field edge more than the center. A small focus shift can make a hardly discernible blurring at the center, but astigmatism off axis quickly rears its ugly head, resembling field rotation.

                      It's important to bear in mind that different optical designs have differing radii of field curvature with respect to focal length. And for a given design, field curvature becomes 'stronger' with decreasing focal length. And one or both of the objective and reducer introduce coma and astigmatism, the amount varying principally with field angle and degree of reduction. With all the possibilities resulting from these variables, the maximal reduction achievable before aberrations become objectionable will vary from system to system.

                      Glenn LeDrew
                      Ottawa

                      --- In mallincam@yahoogroups.com, "glennledrew" <gcledrew@...> wrote:
                      >
                      > Rock,
                      > You're too hard on your MFR-5! Doesn't work so well on Newtonians, you say? I beg to differ! I spent a full night with my VSS+ and MFR-5 (no additional spacers) attached to a friend's Skywatcher 12" f/4.9 GoTo dob, and got very nice results. The working f/ratio was about f/2.45. In order to achieve focus, the handy collapsible struts were pushed down about 1.5" and set with spacers. The only problem at times was some small amount of tracking irregularities, not aberrations introduced by the reducer.
                      >
                      > So... The MFR-5--with no additional spacers at any rate--does work rather well with ~f/5 Newtonians if the focus can be achieved. Perhaps it's because of the more common difficulty of getting to focus due to insufficient in-travel that you point out the incompatibity with Newts. It sure is not an optical incompatibility!
                      >
                      > Therefore, if one really desires to employ the MFR-5 on a Newtonian (around f/5, anyway) it will work if the primary-to-secondary mirror spacing can be reduced sufficiently.
                      >
                      > Glenn LeDrew
                      > Ottawa
                      >
                      > --- In mallincam@yahoogroups.com, "MallinCam" <mallincam@> wrote:
                      > >
                      > > Dom and all,
                      > >
                      > > We have covered this before several times on this list in past post. So, I';ll sound like an old broken record again. (i don't mind)
                      > >
                      > > The MFR-5 was design with two cells of two lenses each working together to achieve a low F/ratio from ANY telescope except a Newtonian type optic to deliver a lower F ratio. First set of lens (front part) is a 0.5.5X reduction and seconds is a CCD CORRECTOR field Flatner made FOR CCD of 1/2" in size only or 0.8X. The amount of reduction can vary from F/2.8 all the way to F/4.5 depending on optics used on. as tested on a optical bench and in the field.
                      > >
                      > > Using a series of spacers where greater distance will change this reduction can be pin point for optimal position between the ccd sensor and MFR-5 to deliver a specific final F ratio.
                      > >
                      > >
                      > > It was mainly design for people who wanted to use a focal reducer with a diagonal to clear the way of the camera when used on a SCT in ALT-AZ just like my own SCT. But, the MFR-5 can be used as well at prime focus through a rear cell adapter of a SCT.
                      > >
                      > > Distance between smaller MFR-5 cell and ccd sensor will dictate the amount of vignetting, amount of uncorrected star field. The MFR-5 picks up what you feed it. If optics are of not "normal range", expect some artifact which needs to be corrected by removing all spacers from the MFR-5. Infrared can also play havoc on final reduction on some refractors and curvature of optics as well will result in artifact. Less reduction is then desired.
                      > >
                      > > MallinCam developed the MFR-5 2 years before Meade and Celestron came out with their ACF and Edge optics. We used a RC to design our MFR-5 and results speaks for itself. Results were spectacular with all refractors tested on which included TeleVue Genesis and many other high end refractors. Maksutov optical design have produced some spectacular result as well with no optical aberration what so ever.
                      > >
                      > > Because the majority of Newtonian are F/5 or less, it is not practical to use a MFR-5 on a Newtonian type telescope. It just don't make sense at all. The MFR-3 was design for all Newtonian type telescopes in aperture of up to 32". We use a 16" F/4.5 to design the MFR-3 on a EQ mount way back then in 2003 -2004. Result again was very consistent lower F ratio with no observable optical aberration. Further improvement have been made on the MFR-3 in later years to incorporate further correction for parabolic curvature of Newtonian design. Lenses used to be hand grounded in our shop and hand made. Any one claiming a MFR-3 is just a "simple regular" focal reducer, have no idea of the work and designing that went through this design for Newtonian and other uses on a variety of telescopes where a "milder" reduction is needed. They surely been miss informed about the product and their optical design for 1/2" ccd video sensor.
                      > >
                      > > Same applies to the MFR-5. A lot of optical engineering went through the design of the MFR-5 and recently new lenses made in Germany with premium optical glass has been further enhanced.
                      > >
                      > > These focal reducers are design for 1/2 ccd work, mainly video ccd and nothing else. Designed and made right here in Ottawa after years of testing and testing thought, results speaks for themselves with a rpoduct especially design for video ccd work.
                      > >
                      > > We cannot guaranty the focal length of any specific telescopes as too many variants are present in any telescopes. Not all scopes are made the same way. Adjusting the MFR-5 and MFR-3 with a series of spacers will make a user achieve a focal length to make his or her image the best observed live.
                      > >
                      > > Rock M.
                      > >
                      > >
                      > >
                      > >
                      > >
                      > >
                      > > --- In mallincam@yahoogroups.com, "dom7mak" <domokos543@> wrote:
                      > > >
                      > > > Mark,
                      > > >
                      > > > The MFR-5 combinations that you tried yield 0.3-0.4x reduction factors. That may be too much for an f/7 refractor. Plus the MFR-5 is designed for spherical mirror f/10 SCT's. It may attempt to correct an aberration that your high class refactor doesn't have.
                      > > >
                      > > > MFR-3 with 10mm spacer produces a 0.65x reduction, which is more appropriate for an f/7 scope. Moreover the the MFR-3 is a straightforward focal reducer. It doesn't attempt to correct anything.
                      > > >
                      > > > --Dom
                      > > >
                      > > > --- In mallincam@yahoogroups.com, "mpetraglia@" <mpetraglia@> wrote:
                      > > > >
                      > > > >
                      > > > > Rock,
                      > > > >
                      > > > > This evening I tried the MFR5 in the following combo's
                      > > > >
                      > > > > -MFR5 with 5m between lens cells
                      > > > > -MFR5 with 10m between lens cells
                      > > > > -MFR5 with 10m between camera and MFR5
                      > > > > -MFR5 with 5m between camera and MFR5
                      > > > > -MFR5 with 5m and 10m (15M) between camera and MFR5
                      > > > >
                      > > > > Still the MFR3 with 10m between camera and MFR3 produced the best results with pin point stars to the edges.
                      > > > >
                      > > > >
                      > > > > --- In mallincam@yahoogroups.com, "MallinCam" <mallincam@> wrote:
                      > > > > >
                      > > > > > Marc
                      > > > > >
                      > > > > > Try the MFR-5 without any spacers. Try adding a 5 mm spacer between both element of the MFR-5. Works on some telescope. That is why the MFR-5 has so many combinations to use for specific telescope. You need to experiment.
                      > > > > >
                      > > > > > Rock M.
                      > > > > >
                      > > > > > --- In mallincam@yahoogroups.com, "mpetraglia@" <mpetraglia@> wrote:
                      > > > > > >
                      > > > > > > I did a test using the MFR5 and MFR3 along with both 5m and 10m spacer between camera and MFRx. I found the following
                      > > > > > >
                      > > > > > > -MFR5 I get coma and it's improved with the 10M between camera and MFR5 but still present
                      > > > > > >
                      > > > > > > -MFR3 with 10M works great. nice round start to the edge of field.
                      > > > > > >
                      > > > > > > Does anyone have any further knowledge or comments to share
                      > > > > > >
                      > > > > > > I'm a bit confused as I've read that I should be using the MFR5 but can;t seem to get rid of the coma
                      > > > > > >
                      > > > > > > Thanks
                      > > > > > > Marc
                      > > > > > >
                      > > > > >
                      > > > >
                      > > >
                      > >
                      >
                    • MallinCam
                      Glenn, Glad you are here. You are correct. The only reason the MFR-5 is not compatible to Newtonian telescope is the in travel required. Not everyone has the
                      Message 10 of 20 , Sep 6, 2012
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                        Glenn,


                        Glad you are here. You are correct. The only reason the MFR-5 is not "compatible" to Newtonian telescope is the in travel required. Not everyone has the ability to do mod on their Newtonian telescope to accommodate the in focus travel needed. This is the reason why we indicated : Not compatible with Newtonian. Otherwise, optically, it is.

                        Rock M.

                        --- In mallincam@yahoogroups.com, "glennledrew" <gcledrew@...> wrote:
                        >
                        > Rock,
                        > You're too hard on your MFR-5! Doesn't work so well on Newtonians, you say? I beg to differ! I spent a full night with my VSS+ and MFR-5 (no additional spacers) attached to a friend's Skywatcher 12" f/4.9 GoTo dob, and got very nice results. The working f/ratio was about f/2.45. In order to achieve focus, the handy collapsible struts were pushed down about 1.5" and set with spacers. The only problem at times was some small amount of tracking irregularities, not aberrations introduced by the reducer.
                        >
                        > So... The MFR-5--with no additional spacers at any rate--does work rather well with ~f/5 Newtonians if the focus can be achieved. Perhaps it's because of the more common difficulty of getting to focus due to insufficient in-travel that you point out the incompatibity with Newts. It sure is not an optical incompatibility!
                        >
                        > Therefore, if one really desires to employ the MFR-5 on a Newtonian (around f/5, anyway) it will work if the primary-to-secondary mirror spacing can be reduced sufficiently.
                        >
                        > Glenn LeDrew
                        > Ottawa
                        >
                        > --- In mallincam@yahoogroups.com, "MallinCam" <mallincam@> wrote:
                        > >
                        > > Dom and all,
                        > >
                        > > We have covered this before several times on this list in past post. So, I';ll sound like an old broken record again. (i don't mind)
                        > >
                        > > The MFR-5 was design with two cells of two lenses each working together to achieve a low F/ratio from ANY telescope except a Newtonian type optic to deliver a lower F ratio. First set of lens (front part) is a 0.5.5X reduction and seconds is a CCD CORRECTOR field Flatner made FOR CCD of 1/2" in size only or 0.8X. The amount of reduction can vary from F/2.8 all the way to F/4.5 depending on optics used on. as tested on a optical bench and in the field.
                        > >
                        > > Using a series of spacers where greater distance will change this reduction can be pin point for optimal position between the ccd sensor and MFR-5 to deliver a specific final F ratio.
                        > >
                        > >
                        > > It was mainly design for people who wanted to use a focal reducer with a diagonal to clear the way of the camera when used on a SCT in ALT-AZ just like my own SCT. But, the MFR-5 can be used as well at prime focus through a rear cell adapter of a SCT.
                        > >
                        > > Distance between smaller MFR-5 cell and ccd sensor will dictate the amount of vignetting, amount of uncorrected star field. The MFR-5 picks up what you feed it. If optics are of not "normal range", expect some artifact which needs to be corrected by removing all spacers from the MFR-5. Infrared can also play havoc on final reduction on some refractors and curvature of optics as well will result in artifact. Less reduction is then desired.
                        > >
                        > > MallinCam developed the MFR-5 2 years before Meade and Celestron came out with their ACF and Edge optics. We used a RC to design our MFR-5 and results speaks for itself. Results were spectacular with all refractors tested on which included TeleVue Genesis and many other high end refractors. Maksutov optical design have produced some spectacular result as well with no optical aberration what so ever.
                        > >
                        > > Because the majority of Newtonian are F/5 or less, it is not practical to use a MFR-5 on a Newtonian type telescope. It just don't make sense at all. The MFR-3 was design for all Newtonian type telescopes in aperture of up to 32". We use a 16" F/4.5 to design the MFR-3 on a EQ mount way back then in 2003 -2004. Result again was very consistent lower F ratio with no observable optical aberration. Further improvement have been made on the MFR-3 in later years to incorporate further correction for parabolic curvature of Newtonian design. Lenses used to be hand grounded in our shop and hand made. Any one claiming a MFR-3 is just a "simple regular" focal reducer, have no idea of the work and designing that went through this design for Newtonian and other uses on a variety of telescopes where a "milder" reduction is needed. They surely been miss informed about the product and their optical design for 1/2" ccd video sensor.
                        > >
                        > > Same applies to the MFR-5. A lot of optical engineering went through the design of the MFR-5 and recently new lenses made in Germany with premium optical glass has been further enhanced.
                        > >
                        > > These focal reducers are design for 1/2 ccd work, mainly video ccd and nothing else. Designed and made right here in Ottawa after years of testing and testing thought, results speaks for themselves with a rpoduct especially design for video ccd work.
                        > >
                        > > We cannot guaranty the focal length of any specific telescopes as too many variants are present in any telescopes. Not all scopes are made the same way. Adjusting the MFR-5 and MFR-3 with a series of spacers will make a user achieve a focal length to make his or her image the best observed live.
                        > >
                        > > Rock M.
                        > >
                        > >
                        > >
                        > >
                        > >
                        > >
                        > > --- In mallincam@yahoogroups.com, "dom7mak" <domokos543@> wrote:
                        > > >
                        > > > Mark,
                        > > >
                        > > > The MFR-5 combinations that you tried yield 0.3-0.4x reduction factors. That may be too much for an f/7 refractor. Plus the MFR-5 is designed for spherical mirror f/10 SCT's. It may attempt to correct an aberration that your high class refactor doesn't have.
                        > > >
                        > > > MFR-3 with 10mm spacer produces a 0.65x reduction, which is more appropriate for an f/7 scope. Moreover the the MFR-3 is a straightforward focal reducer. It doesn't attempt to correct anything.
                        > > >
                        > > > --Dom
                        > > >
                        > > > --- In mallincam@yahoogroups.com, "mpetraglia@" <mpetraglia@> wrote:
                        > > > >
                        > > > >
                        > > > > Rock,
                        > > > >
                        > > > > This evening I tried the MFR5 in the following combo's
                        > > > >
                        > > > > -MFR5 with 5m between lens cells
                        > > > > -MFR5 with 10m between lens cells
                        > > > > -MFR5 with 10m between camera and MFR5
                        > > > > -MFR5 with 5m between camera and MFR5
                        > > > > -MFR5 with 5m and 10m (15M) between camera and MFR5
                        > > > >
                        > > > > Still the MFR3 with 10m between camera and MFR3 produced the best results with pin point stars to the edges.
                        > > > >
                        > > > >
                        > > > > --- In mallincam@yahoogroups.com, "MallinCam" <mallincam@> wrote:
                        > > > > >
                        > > > > > Marc
                        > > > > >
                        > > > > > Try the MFR-5 without any spacers. Try adding a 5 mm spacer between both element of the MFR-5. Works on some telescope. That is why the MFR-5 has so many combinations to use for specific telescope. You need to experiment.
                        > > > > >
                        > > > > > Rock M.
                        > > > > >
                        > > > > > --- In mallincam@yahoogroups.com, "mpetraglia@" <mpetraglia@> wrote:
                        > > > > > >
                        > > > > > > I did a test using the MFR5 and MFR3 along with both 5m and 10m spacer between camera and MFRx. I found the following
                        > > > > > >
                        > > > > > > -MFR5 I get coma and it's improved with the 10M between camera and MFR5 but still present
                        > > > > > >
                        > > > > > > -MFR3 with 10M works great. nice round start to the edge of field.
                        > > > > > >
                        > > > > > > Does anyone have any further knowledge or comments to share
                        > > > > > >
                        > > > > > > I'm a bit confused as I've read that I should be using the MFR5 but can;t seem to get rid of the coma
                        > > > > > >
                        > > > > > > Thanks
                        > > > > > > Marc
                        > > > > > >
                        > > > > >
                        > > > >
                        > > >
                        > >
                        >
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