Loading ...
Sorry, an error occurred while loading the content.

Re: TMB 100/800 Startesting with CCD Camera for Pool checking

Expand Messages
  • postmaster@voltaire.csun.edu
    ... inside ... ======================================================== Hi Markus, Cool startest images! I took the liberty of combining all four images into
    Message 1 of 10 , Apr 5, 2001
    • 0 Attachment
      --- In tmboptical@y..., apm_telescopes@w... wrote:
      > Hi All,
      >
      > on Mike's request I just made 4 similar sizest CCD Images with
      inside
      > focuse and outside focuse.
      >
      >
      > if you can load all 4 images together on your monitor , than you may
      > will see, why we at APM and even TMB have big problems to select the
      > higher or lower quality by startesting even on bench it provides
      > problems to tell which is the better lens.
      >
      > when the pool is closed I will post the interferometrical testreport
      > on the files
      >
      > Now I am very interested who will be able to tell me which lens is
      > better.
      > Please dont make lotterie, we like to know why you have the
      > impression one lens have better numbers than the others. Explain it
      > if possible with an statement
      >
      > good luck
      >
      > Markus
      ========================================================
      Hi Markus,
      Cool startest images! I took the liberty of combining all four images
      into one JPG file to make this little poll a bit easier. The combined
      image can be found in the files section. The image is called
      comb_star_test.JPG

      Best,
      Robert Provin
    • demary@arlut.utexas.edu
      The poll needs a 3rd choice: the two lenses look about the same to me. What artifact produces the double images? Dust on the collimator? I see nothing like
      Message 2 of 10 , Apr 5, 2001
      • 0 Attachment
        The poll needs a 3rd choice: the two lenses look about the
        same to me.

        What artifact produces the double images? Dust on the collimator?
        I see nothing like that in a star test on a real star.

        Tom DeMary
      • TMBoptical@aol.com
        ... Hi Tom, That s a good sign! ... I just want to point out a few things about these images. You may notice the lack of circularity in two of the inside of
        Message 3 of 10 , Apr 5, 2001
        • 0 Attachment
          --- In tmboptical@y..., demary@a... wrote:
          > The poll needs a 3rd choice: the two lenses look about the
          > same to me.

          Hi Tom,

          That's a good sign!

          > What artifact produces the double images? Dust on the collimator?
          > I see nothing like that in a star test on a real star.
          >
          > Tom DeMary

          I just want to point out a few things about these images.
          You may notice the lack of circularity in two of the inside
          of focus images. This is due to the autocollimation setup
          that Markus uses. There is some vignetting, as the clear
          aperture is not quite big enough at that focal setting
          (he is not using a large flat, but an autocollimation
          telescope of known, very high quality). The artifacts are
          due to dust motes, which are exceeding hard to eliminate
          in this type of setup. They are normal, and are not what
          you would see in a real star test. Also, any color seen
          in these images are a function of any color artifacts in
          the entire system, including the camera, eyepiece, and
          collimation telescope. These colors are not seen visually.

          Thomas Back
          TMB Optical
        • k5apl@cs.com
          Thanks Robert for doing this. Wes
          Message 4 of 10 , Apr 5, 2001
          • 0 Attachment
            Thanks Robert for doing this.
            Wes
          • a_potentate@hotmail.com
            It looks to me to be impossible to tell them apart visually. Markus, Since you have this set up could you also post the at-focus star images?
            Message 5 of 10 , Apr 5, 2001
            • 0 Attachment
              It looks to me to be impossible to tell them
              apart visually.


              Markus,


              Since you have this set up could you also post the
              at-focus star images? <if not too much trouble>


              Thanks

              Tim
            • Markus Ludes
              a super mini dust particle maybe on the projection eyepiece, at that higher power its easy to see, have nothing to do with the lens Markus ... From:
              Message 6 of 10 , Apr 5, 2001
              • 0 Attachment
                a super mini dust particle maybe on the projection eyepiece, at that higher power its easy to see, have nothing to do with the lens
                 
                Markus
                ----- Original Message -----
                Sent: Thursday, April 05, 2001 6:06 PM
                Subject: [tmboptical] Re: TMB 100/800 Startesting with CCD Camera for Pool checking

                The poll needs a 3rd choice:  the two lenses look about the
                same to me.

                What artifact produces the double images?  Dust on the collimator?
                I see nothing like that in a star test on a real star.

                Tom DeMary



                To unsubscribe from this group, send an email to:
                tmboptical-unsubscribe@egroups.com



                Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
              • Markus Ludes
                ... I just want to point out a few things about these images. You may notice the lack of circularity in two of the inside of focus images. This is due to the
                Message 7 of 10 , Apr 5, 2001
                • 0 Attachment
                   
                  ----- Original > Tom DeMary

                     I just want to point out a few things about these images.
                  You may notice the lack of circularity in two of the inside
                  of focus images. This is due to the autocollimation setup
                  that Markus uses. There is some vignetting, as the clear
                  aperture is not quite big enough at that focal setting
                  (he is not using a large flat, but an autocollimation
                  telescope of known, very high quality).
                   
                  correct
                   
                   
                   The artifacts are
                  due to dust motes, which are exceeding hard to eliminate
                  in this type of setup. They are normal, and are not what
                  you would see in a real star test.
                   
                  it must be an mini dustparticle on the collimator projectionlens, will try it next time with an new clean lens
                   
                   Also, any color seen
                  in these images are a function of any color artifacts in
                  the entire system, including the camera, eyepiece, and
                  collimation telescope. These colors are not seen visually.
                  thats correct
                   
                  Markus


                  Thomas Back
                  TMB Optical



                  To unsubscribe from this group, send an email to:
                  tmboptical-unsubscribe@egroups.com



                  Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
                • Markus Ludes
                  the infocus star images I can make only after the remote controll for my camera arrives, which is backordered. Please note this images are 6 second images,
                  Message 8 of 10 , Apr 5, 2001
                  • 0 Attachment
                    the infocus star images I can make only after the remote controll for my camera arrives, which is backordered. Please note this images are 6 second images, where the botton is pushed by my hands and shakes at least 2 seconds.
                     
                    When the remote controll arrives, than automaticly first the shutter gets open and only than the image will be done and I can use short enough exporshures for the infocuse images, please wait a little bit
                     
                    Markus
                    ----- Original Message -----
                    Sent: Thursday, April 05, 2001 9:08 PM
                    Subject: [tmboptical] Re: TMB 100/800 Startesting with CCD Camera for Pool checking



                    It looks to me to be impossible to tell them
                    apart visually.


                    Markus,


                    Since you have this set up could you also post the
                    at-focus star images?  <if not too much trouble>


                    Thanks

                    Tim



                    To unsubscribe from this group, send an email to:
                    tmboptical-unsubscribe@egroups.com



                    Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
                  • demary@arlut.utexas.edu
                    ... I knew it was not the lens. My own 100 f/8 makes very clean, color-fringe-free out-of-focus stellar discs. The last time I used my 3mm Radian (and
                    Message 9 of 10 , Apr 5, 2001
                    • 0 Attachment
                      --- In tmboptical@y..., "Markus Ludes" <apm_telescopes@w...> wrote:
                      > a super mini dust particle maybe on the projection eyepiece, at
                      > that higher power its easy to see, have nothing to do with the
                      > lens.

                      I knew it was not the lens. My own 100 f/8 makes very clean,
                      color-fringe-free out-of-focus stellar discs.


                      The last time I used my 3mm Radian (and TMB-180) on the moon,
                      I noticed a couple of dark spots which were somewhere in my
                      optical path. I thought that maybe my diagonal was dirty, but
                      it was actually some tiny debris on the eyelens of the 3 mm
                      Radian. I have never seen anything like that with my longer
                      focal length eyepieces.

                      Tom DeMary
                    Your message has been successfully submitted and would be delivered to recipients shortly.