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

Re: [LX200GPS]OFF-LIST Re: Strange reflection (looks like a lissajous figure)

Expand Messages
  • Paul A. Valleli
    Chris, I understand your pain. Many amateurs convert to armchair astronomy at about 65. After several years of driving 120 miles to VT to use the 13-inch
    Message 1 of 22 , Oct 31, 2011
    • 0 Attachment
      Chris,
      I understand your pain. Many amateurs convert to
      'armchair astronomy' at about 65.

      After several years of driving 120 miles to VT to
      use the 13-inch Schupmann through the seasons, I
      decided to make some significant engineering
      compromises and re-built my roll-off with a C-8 that
      was carried indoors each time,and I invested in a
      domed observatory.
      I can only observe above 45 deg. and the light
      pollution is terrible. The Meade14-inch LX200R was
      used but in excellent condition and I have been
      slowly working toward automation so I can observe in
      the warmth of my office/lab. I reach 16th mag.
      without filters or stacking and have hope of getting
      to 20th in narrow bands when I get a good science
      camera.
      Paul




      ---- Original message ----

      Date: Mon, 31 Oct 2011 20:58:55 -0000
      From: "Chris Strang" <chrisstrang@...>
      Subject: [LX200GPS] Re: Strange reflection (looks
      like a lissajous figure)
      To: LX200GPS@yahoogroups.com



      Thanks again Starman, I think we may be on to a
      solution. Now maybe you (or anyone) can solve my
      other problem being the guru you are. On the said
      outing, I was 200 miles from home in an open
      field, no AC, 3:00 AM, ice all over everything, it
      is 20 deg. F, I am cold and wet, the battery for
      my dew heaters about dead, and the only place to
      sleep is in the back of my cold pick-up truck. THE
      QUESTION IS, how do you turn on the brain of this
      77 year old man and tell him to get a life?
      My apology to the Moderator and others for my
      babble.
      Chris

      --- In LX200GPS@yahoogroups.com, "Paul A. Valleli"
      <valleli@...> wrote:
      >
      > Chris,
      > Point the scope at the Moon or a bright planet
      or
      > star. Remove the eyepiece and place your eye in
      its
      > place and look toward the secondary. Any
      reflections
      > from the draw tube, focuser, or other sources
      will
      > "knock your eye out". Apply PSA Black Velvet or
      > ultra flat black to the offending areas.
      >
      > Starman Paul
      > ---- Original message ----
      >
      > Date: Mon, 31 Oct 2011 05:34:12 -0000
      > From: "Chris Strang" <chrisstrang@...>
      > Subject: [LX200GPS] Re: Strange reflection
      (looks
      > like a lissajous figure)
      > To: LX200GPS@yahoogroups.com
      >
      >
      >
      > Thanks Ian for the info, you made my
      "day"(night)
      > with the good news. I am a serious imager with
      > average-plus skills. I have only seen this
      problem
      > about 4 times in 3 years and then only with a
      > bright off-axis star using a long exposure,
      > field-flattener, and ZS focuser. I do not think
      > the focuser is the problem, but when the camera
      is
      > extended well over 4 inches from the F/R the
      > chance of reflections greatly increase. But my
      > reason for the posting was I had popes someone
      > else had solved this problem before. The big
      plus
      > is that I have met some very interesting people.
      I
      > am impressed at knowledge base of this group.
      > Thanks again everyone, Chris
      >
      > --- In LX200GPS@yahoogroups.com, "ian matterson"
      > <ian.matterson@> wrote:
      > >
      > > Hi Chris,
      > > the good new is that the corrector plate
      > position is the only one that is critical, the
      > secondary mirror is spherical and just needs to
      be
      > positioned so that corrections can be made for
      > collimation.
      > > On my lx the top adjustment screw (bobs knobs)
      > is positioned JUST BEFORE 1oclock.
      > >
      > > Have you always had this reflection issue, and
      > how did you workout that the zero shift focuser
      > was causing light path issue's (just curious).
      > > Also its best not to use a F/R when you
      > collimate, start of with a low powered EP and
      then
      > include a barlow, if you have a guide cam, use
      > that as well, it saves time and effort.
      > >
      > > Good luck tracking down the primary cause of
      > your reflection, I'm sure you will soon, keep us
      > posted with your progress
      > >
      > > Clear1's

      > > Ian Matterson
      > >
      > >
      > >
      > > ----- Original Message -----
      > > From: Chris Strang
      > > Sent: 31/10/11 01:00 AM
      > > To: LX200GPS@yahoogroups.com
      > > Subject: [LX200GPS] Re: Strange reflection
      > (looks like a lissajous figure)
      > >
      > > I believe also it is the camera, but for
      > different reasions. The exposures are over 600
      sec
      > so short term vibrations should have a mimimal
      > effect.
      > > I suspect I have more than one problem, but
      hope
      > it is not the secondary as suggested by Dick. My
      > guess is that I am getting reflections off the
      > exit port and also some off-axis reflections
      > bouncing between the camera chip and the field
      > flattener.The camera is DSLR Canon 450D modified

      > by Hutech.
      > > Thanks for your note.
      > > Chris
      > >
      > > --- In LX200GPS%2540yahoogroups.com , Colin
      Haig
      > <telescope@> wrote:
      > > >
      > > > Chris - What's the camera ?
      > > > Besides all the suggestions from other folk
      on
      > eliminating the
      > > > internal reflections, I'm thinking you're
      > using a DSLR, and you
      > > > havent allowed enough time for mirror to
      > settle. If you can, try
      > > > turning on mirror lock up. I suspect the
      > internal reflections are
      > > > getting picked up by mirror motion /
      vibration
      > until it settles.
      > > > Good luck,
      > > > Colin
      > > >
      > > > At 01:54 AM 2011-10-29, Chris Strang wrote:
      > > > >Does anyone know what is causing lissajous
      > like reflections in my
      > > > >LX200GPS-8? When I am imaging the sky that
      > has a bright star
      > > > >(Alnitak) I at times get strange
      refiections.
      > Most of the time I am
      > > > >using a field flattener and a Microfocuser
      > which puts the
      > > > >focal-plane back about 4 inches. I don't
      > believe it is caused from dew.
      > > > >See an example from the link below.

      > > > >Chris.
      > > > >
      > > > >
      > > >
      >
      >http://groups.yahoo.com/group/LX200GPS/photos/album/1108451930/pic/2032870457/view?picmode=&mode=tn&order=ordinal&start=1&count=20&dir=asc
      > > > >
      > > > >
      > > > >
      > > > >
      > > > >------------------------------------
      > > > >
      > > > >Yahoo! Groups Links
      > > > >
      > > > >
      > > > >
      > > >
      > >
      > >
      > >
      > >
      > > [Non-text portions of this message have been
      > removed]
      > >
      >
      >
      >
      >
      > [Non-text portions of this message have been
      removed]
      >




      [Non-text portions of this message have been removed]
    • Dave Herald
      Its interesting to do a Google search on the Narcissus effect (aberration). To quote from.
      Message 2 of 22 , Oct 31, 2011
      • 0 Attachment
        Its interesting to do a Google search on the Narcissus effect (aberration). To quote from.
        http://books.google.com.au/books?id=mberzJtkU4MC&pg=PA249&lpg=PA249&dq=Narcissus+aberrations&source=bl&ots=1thW5zL4Pd&sig=4d01WiU4klHckbBZuVq6rRtEXks&hl=en&ei=TGyvTumnIK-ZiAeCksDhAg&sa=X&oi=book_result&ct=result&resnum=1&ved=0CCEQ6AEwAA#v=onepage&q=Narcissus%20aberrations&f=false

        [which is a book on ‘Fundamental optical design’ by Michael J Kidger]

        “The problem is unique to infrared systems with cooled detectors. Narcissus is the effect by which a reflection of the detector and its surround occurs over only the central part of the field of view. Its appearance is that of a cold circular shadow with a sharp edge overlaid on the scene.....

        This doesn’t sound quite like the issuer with your image. I trust those that assert that your image involves the Narcissus effect have correctly diagnosed your image.

        Dave Herald
        Murrumbateman, Australia


        From: Paul A. Valleli
        Sent: Tuesday, November 01, 2011 2:31 PM
        To: LX200GPS@yahoogroups.com
        Subject: Re: [LX200GPS] Re: Strange reflection (looks like a lissajous figure)
        Chris,
        This is not a hypothetical situation, but
        demonstrated by several professionals and jointly
        agreed as to the source. I am five years younger
        than you and understand ornery persistance and
        honest skepticism. It is a trademark of good
        science. I also bow to the experience of Dennis
        diCicco as a master astrophotographer.
        In the last 30 - 40 years, optical scientists and
        engineers have worked very hard to learn the causes
        and limited solutions to Narcissus. Without their
        effort, we would not have viable security and
        reconnaissance imagery in the infrared.

        As an experiment, dump the microfocuser and put the
        camera close and then far from the back of the OTA.
        Say 1 and 10 inches. There should be a noticable
        change in the ghost size and shape.

        Changing to a different CCD may show a difference,
        also.
        Starman Paul


        ---- Original message ----

        Date: Mon, 31 Oct 2011 16:57:09 -0000
        From: "Chris Strang" <chrisstrang@...>
        Subject: [LX200GPS] Re: Strange reflection (looks
        like a lissajous figure)
        To: LX200GPS@yahoogroups.com



        Starman Paul, I like your writing style. Thanks
        for your analyses/hypothesis, but as you can
        imagine I am not thrilled with your prognosis for
        my success. In reference to your parting comment,
        I have the ability, but am not sure about the
        energy. Like "many have tried" I have some traits
        that are in opposition. One is I like results, so
        in the past I did essentially what you suggested
        and cloned out any aberration. The other is I am
        stubborn, and at 3:00 AM, cold, ice and dew on
        everything, no sleep for 20 hours I want results.
        Equipment running excellently so I "goto" the
        Horse Head, take a short registration image.
        Dead-on. No aberrations. Rotate only the camera to
        get the Flame. Wham, reflections all over the
        image. Move the tube toward the Flame about 15
        minutes. The reflections on each side of the
        imaged got closer. You guessed it, I packed it in.
        Thanks for your excellent analyses, and at my age
        maybe I should forget about taking the Horse He!
        ad and just go to "picture of the day" if I want
        one.
        Chris

        --- In LX200GPS@yahoogroups.com, "Paul A. Valleli"
        <valleli@...> wrote:
        >
        > Well Chris, many have tried, a few are close,
        but
        > the answer to the cause of your weird
        > images was given by Dennis diCicco in S&T many
        years
        > ago.
        > Normally, Narcissis, is not considered an
        optical
        > aberration but is the nemesis of Infrared
        > photographers. It means the detector is looking
        at a
        > reflection of itself. In many scopes like Cass.
        and
        > R-C it is a reflection in the center of the
        convex
        > secondary.
        > In your case, it is much more sneaky and less
        > obvious source. The CCD and CMOS detectors have
        a
        > reflectance around 10%, maybe more.
        Manufacturers
        > try to minimize it.
        >
        > When a bright star is brought into focus on the
        > CCD, some of the light acts as a point source
        and is
        > reflected back toward the secondary. This hits
        the
        > secondary surface, bounces off, and expands back
        to
        > fill the primary mirror. The primary
        approximately
        > collimates the rays and directs it back toward
        the
        > star. The light is intercepted by both the rear
        and
        > front surfaces of the corrector plate. Since
        those
        > surfaces are approximately flat, they reflect
        some
        > of the light back to the detector.
        > This is a classic example of the autocollimation
        > test for telescopes. The reflections may have
        > different colors, depending on whether there is
        > plain glass, magnesium fluoride, or a
        sophisticated
        > UHTC multi-layer coating.
        > The plane surface yields the out-of-focus
        'cats-eye
        > dougnut' and the aspherical surface creates an
        image
        > that looks like the Starship Enterprise on its
        side.
        > The corrector may be purposely tilted by the
        > manufacturer and if you removed it, lost a shim,

        > or may have lost the tilt angle. Retaining
        screws on
        > the corrector retainer should only be finger
        tight.
        >
        > Without any auxiliary optics like F.F.'s or
        F.R.'s,
        > look up the barrel of the baffle tube while your
        eye
        > is in the center. All reflections of the
        perimeters
        > of the optical components should be concentric.
        Look
        > through a peephole to be sure your eye is
        centered.
        > If the reflections are eccentric, then
        collimation
        > is necessary. The manufacturers have permanently
        > attached the primary to its focusing "sled" so
        it
        > becomes the reference for the rest of the
        system.
        > Tilting the secondary with the three screws
        assumes
        > both secondary and corrector are concentric to
        the
        > primary.
        > Follow the alignment procedures on this group
        list
        > and forget the expensive laser collimator, it
        was
        > not designed for aligning an S-C or Cass.
        > Verify on bright star images at high EP power.
        (80X
        > to 150X) - There should be no visible assymetry
        > except atmospheric turbulence.
        >
        > Of course, if this fails your ability, you could
        > crop out the offending defects !
        >
        > Starman Paul, retired optical engineer.
        >
        > ---- Original message ----
        >
        > Date: Mon, 31 Oct 2011 01:00:56 -0000
        > From: "Chris Strang" <chrisstrang@...>
        > Subject: [LX200GPS] Re: Strange reflection
        (looks
        > like a lissajous figure)
        > To: LX200GPS@yahoogroups.com
        >
        >
        >
        > I believe also it is the camera, but for
        different
        > reasions. The exposures are over 600 sec so
        short
        > term vibrations should have a mimimal effect.
        > I suspect I have more than one problem, but hope
        > it is not the secondary as suggested by Dick. My
        > guess is that I am getting reflections off the
        > exit port and also some off-axis reflections
        > bouncing between the camera chip and the field
        > flattener.The camera is DSLR Canon 450D modified
        > by Hutech.
        > Thanks for your note.
        > Chris
        >
        > --- In LX200GPS@yahoogroups.com, Colin Haig
        > <telescope@> wrote:
        > >
        > > Chris - What's the camera ?
        > > Besides all the suggestions from other folk on
        > eliminating the
        > > internal reflections, I'm thinking you're
        using
        > a DSLR, and you
        > > havent allowed enough time for mirror to
        settle.
        > If you can, try
        > > turning on mirror lock up. I suspect the
        > internal reflections are
        > > getting picked up by mirror motion / vibration
        > until it settles.
        > > Good luck,
        > > Colin
        > >
        > > At 01:54 AM 2011-10-29, Chris Strang wrote:
        > > >Does anyone know what is causing lissajous
        like
        > reflections in my
        > > >LX200GPS-8? When I am imaging the sky that
        has
        > a bright star
        > > >(Alnitak) I at times get strange refiections.
        > Most of the time I am
        > > >using a field flattener and a Microfocuser
        > which puts the
        > > >focal-plane back about 4 inches. I don't
        > believe it is caused from dew.
        > > >See an example from the link below.
        > > >Chris.
        > > >
        > > >
        > >
        >
        >http://groups.yahoo.com/group/LX200GPS/photos/album/1108451930/pic/2032870457/view?picmode=&mode=tn&order=ordinal&start=1&count=20&dir=asc
        > > >
        > > >
        > > >
        > > >
        > > >------------------------------------
        >
        > > >
        > > >Yahoo! Groups Links
        > > >
        > > >
        > > >
        > >
        >
        >
        >
        >
        > [Non-text portions of this message have been
        removed]
        >




        [Non-text portions of this message have been removed]



        ------------------------------------

        Yahoo! Groups Links




        [Non-text portions of this message have been removed]
      • Paul A. Valleli
        Dave, If there was an internal reflection from the inside of a cylindrical surface such as the EP tube, it would have one of a family of cardioid shapes. The
        Message 3 of 22 , Nov 2, 2011
        • 0 Attachment
          Dave,
          If there was an internal reflection from the inside
          of a cylindrical surface such as the EP tube, it
          would have one of a family of cardioid shapes. The
          "Lissajous" shape is unique to the aspheric, but
          nearly plain surface, of the slightly tilted Schmidt
          Corrector. It's size will vary with the distance
          from the nominal focal plane when the optics are
          spaced at the design position. That's something we
          frequently violate by putting the camera at
          different distance in front of or in back of the
          nominal position ( manufacturers don't even tell
          their customers what that position is as it would
          restrict the flexibility of the telescope).

          Kidger is incorrect to state that Narcissus is
          "unique" to IR systems. The great sensitivity of
          CCD and CMOS detectors extends the effect into the
          Visible and UV because those detectors are not
          perfect absorbers.

          Starman Paul

          ---- Original message ----

          Date: Tue, 1 Nov 2011 15:06:21 +1100
          From: "Dave Herald" <drherald@...>
          Subject: Re: [LX200GPS] Re: Strange reflection
          (looks like a lissajous figure)
          To: <LX200GPS@yahoogroups.com>



          Its interesting to do a Google search on the
          Narcissus effect (aberration). To quote from.
          http://books.google.com.au/books?id=mberzJtkU4MC&pg=PA249&lpg=PA249&dq=Narcissus+aberrations&source=bl&ots=1thW5zL4Pd&sig=4d01WiU4klHckbBZuVq6rRtEXks&hl=en&ei=TGyvTumnIK-ZiAeCksDhAg&sa=X&oi=book_result&ct=result&resnum=1&ved=0CCEQ6AEwAA#v=onepage&q=Narcissus%20aberrations&f=false

          [which is a book on 'Fundamental optical
          design' by Michael J Kidger]

          "The problem is unique to infrared systems with
          cooled detectors. Narcissus is the effect by which
          a reflection of the detector and its surround
          occurs over only the central part of the field of
          view. Its appearance is that of a cold circular
          shadow with a sharp edge overlaid on the
          scene.....

          This doesn't sound quite like the issuer with
          your image. I trust those that assert that your
          image involves the Narcissus effect have correctly
          diagnosed your image.

          Dave Herald
          Murrumbateman, Australia

          From: Paul A. Valleli
          Sent: Tuesday, November 01, 2011 2:31 PM
          To: LX200GPS@yahoogroups.com
          Subject: Re: [LX200GPS] Re: Strange reflection
          (looks like a lissajous figure)
          Chris,
          This is not a hypothetical situation, but
          demonstrated by several professionals and jointly
          agreed as to the source. I am five years younger
          than you and understand ornery persistance and
          honest skepticism. It is a trademark of good
          science. I also bow to the experience of Dennis
          diCicco as a master astrophotographer.
          In the last 30 - 40 years, optical scientists and
          engineers have worked very hard to learn the
          causes
          and limited solutions to Narcissus. Without their
          effort, we would not have viable security and
          reconnaissance imagery in the infrared.

          As an experiment, dump the microfocuser and put
          the
          camera close and then far from the back of the
          OTA.
          Say 1 and 10 inches. There should be a noticable
          change in the ghost size and shape.

          Changing to a different CCD may show a difference,
          also.
          Starman Paul

          ---- Original message ----

          Date: Mon, 31 Oct 2011 16:57:09 -0000
          From: "Chris Strang" <chrisstrang@...>
          Subject: [LX200GPS] Re: Strange reflection (looks
          like a lissajous figure)
          To: LX200GPS@yahoogroups.com

          Starman Paul, I like your writing style. Thanks
          for your analyses/hypothesis, but as you can
          imagine I am not thrilled with your prognosis for
          my success. In reference to your parting comment,
          I have the ability, but am not sure about the
          energy. Like "many have tried" I have some traits
          that are in opposition. One is I like results, so
          in the past I did essentially what you suggested
          and cloned out any aberration. The other is I am
          stubborn, and at 3:00 AM, cold, ice and dew on
          everything, no sleep for 20 hours I want results.
          Equipment running excellently so I "goto" the
          Horse Head, take a short registration image.
          Dead-on. No aberrations. Rotate only the camera to
          get the Flame. Wham, reflections all over the
          image. Move the tube toward the Flame about 15
          minutes. The reflections on each side of the
          imaged got closer. You guessed it, I packed it in.
          Thanks for your excellent analyses, and at my age
          maybe I should forget about taking the Horse He!
          ad and just go to "picture of the day" if I want
          one.
          Chris

          --- In LX200GPS@yahoogroups.com, "Paul A. Valleli"
          <valleli@...> wrote:
          >
          > Well Chris, many have tried, a few are close,
          but
          > the answer to the cause of your weird
          > images was given by Dennis diCicco in S&T many
          years
          > ago.
          > Normally, Narcissis, is not considered an
          optical
          > aberration but is the nemesis of Infrared
          > photographers. It means the detector is looking
          at a
          > reflection of itself. In many scopes like Cass.
          and
          > R-C it is a reflection in the center of the
          convex
          > secondary.
          > In your case, it is much more sneaky and less
          > obvious source. The CCD and CMOS detectors have
          a
          > reflectance around 10%, maybe more.
          Manufacturers
          > try to minimize it.
          >
          > When a bright star is brought into focus on the
          > CCD, some of the light acts as a point source
          and is
          > reflected back toward the secondary. This hits
          the
          > secondary surface, bounces off, and expands back
          to
          > fill the primary mirror. The primary
          approximately
          > collimates the rays and directs it back toward
          the
          > star. The light is intercepted by both the rear
          and
          > front surfaces of the corrector plate. Since
          those
          > surfaces are approximately flat, they reflect
          some
          > of the light back to the detector.
          > This is a classic example of the autocollimation
          > test for telescopes. The reflections may have
          > different colors, depending on whether there is
          > plain glass, magnesium fluoride, or a
          sophisticated
          > UHTC multi-layer coating.
          > The plane surface yields the out-of-focus
          'cats-eye
          > dougnut' and the aspherical surface creates an
          image
          > that looks like the Starship Enterprise on its
          side.
          > The corrector may be purposely tilted by the
          > manufacturer and if you removed it, lost a shim,

          > or may have lost the tilt angle. Retaining
          screws on
          > the corrector retainer should only be finger
          tight.
          >
          > Without any auxiliary optics like F.F.'s or
          F.R.'s,
          > look up the barrel of the baffle tube while your
          eye
          > is in the center. All reflections of the
          perimeters
          > of the optical components should be concentric.
          Look
          > through a peephole to be sure your eye is
          centered.
          > If the reflections are eccentric, then
          collimation
          > is necessary. The manufacturers have permanently
          > attached the primary to its focusing "sled" so
          it
          > becomes the reference for the rest of the
          system.
          > Tilting the secondary with the three screws
          assumes
          > both secondary and corrector are concentric to
          the
          > primary.
          > Follow the alignment procedures on this group
          list
          > and forget the expensive laser collimator, it
          was
          > not designed for aligning an S-C or Cass.
          > Verify on bright star images at high EP power.
          (80X
          > to 150X) - There should be no visible assymetry
          > except atmospheric turbulence.
          >
          > Of course, if this fails your ability, you could
          > crop out the offending defects !
          >
          > Starman Paul, retired optical engineer.
          >
          > ---- Original message ----
          >
          > Date: Mon, 31 Oct 2011 01:00:56 -0000
          > From: "Chris Strang" <chrisstrang@...>
          > Subject: [LX200GPS] Re: Strange reflection
          (looks
          > like a lissajous figure)
          > To: LX200GPS@yahoogroups.com
          >
          >
          >
          > I believe also it is the camera, but for
          different
          > reasions. The exposures are over 600 sec so
          short
          > term vibrations should have a mimimal effect.
          > I suspect I have more than one problem, but hope
          > it is not the secondary as suggested by Dick. My
          > guess is that I am getting reflections off the
          > exit port and also some off-axis reflections
          > bouncing between the camera chip and the field
          > flattener.The camera is DSLR Canon 450D modified
          > by Hutech.
          > Thanks for your note.
          > Chris
          >

          > --- In LX200GPS@yahoogroups.com, Colin Haig
          > <telescope@> wrote:
          > >
          > > Chris - What's the camera ?
          > > Besides all the suggestions from other folk on
          > eliminating the
          > > internal reflections, I'm thinking you're
          using
          > a DSLR, and you
          > > havent allowed enough time for mirror to
          settle.
          > If you can, try
          > > turning on mirror lock up. I suspect the
          > internal reflections are
          > > getting picked up by mirror motion / vibration
          > until it settles.
          > > Good luck,
          > > Colin
          > >
          > > At 01:54 AM 2011-10-29, Chris Strang wrote:
          > > >Does anyone know what is causing lissajous
          like
          > reflections in my
          > > >LX200GPS-8? When I am imaging the sky that

          has
          > a bright star
          > > >(Alnitak) I at times get strange refiections.
          > Most of the time I am
          > > >using a field flattener and a Microfocuser
          > which puts the
          > > >focal-plane back about 4 inches. I don't
          > believe it is caused from dew.
          > > >See an example from the link below.
          > > >Chris.
          > > >
          > > >
          > >
          >
          >http://groups.yahoo.com/group/LX200GPS/photos/album/1108451930/pic/2032870457/view?picmode=&mode=tn&order=ordinal&start=1&count=20&dir=asc
          > > >
          > > >
          > > >
          > > >
          > > >------------------------------------
          >
          > > >
          > > >Yahoo! Groups Links
          > > >
          > > >
          > > >
          > >
          >
          >
          >
          >
          > [Non-text portions of this message have been
          removed]
          >

          [Non-text portions of this message have been
          removed]

          ------------------------------------

          Yahoo! Groups Links

          [Non-text portions of this message have been
          removed]




          [Non-text portions of this message have been removed]
        • Lawrence
          ... Not a chance..... regards Lawrence Harris ;-)
          Message 4 of 22 , Nov 2, 2011
          • 0 Attachment
            >
            > Chris,
            > I understand your pain. Many amateurs convert to
            > 'armchair astronomy' at about 65.

            Not a chance.....

            regards

            Lawrence Harris ;-)
          • larry taborek
            Chris,   I camp at times and have found these chairs very easy to get in and out of and comfortable enough to sleep in.  
            Message 5 of 22 , Nov 2, 2011
            • 0 Attachment
              Chris,
               
              I camp at times and have found these chairs very easy to get in and out of and comfortable enough to sleep in.
               
              http://www.campingworld.com/shopping/item/big-and-tall-harbor-mist-recliner/54592
               
              Larry

              From: Chris Strang <chrisstrang@...>
              To: LX200GPS@yahoogroups.com
              Sent: Monday, October 31, 2011 4:58 PM
              Subject: [LX200GPS] Re: Strange reflection (looks like a lissajous figure)


               
              Thanks again Starman, I think we may be on to a solution. Now maybe you (or anyone) can solve my other problem being the guru you are. On the said outing, I was 200 miles from home in an open field, no AC, 3:00 AM, ice all over everything, it is 20 deg. F, I am cold and wet, the battery for my dew heaters about dead, and the only place to sleep is in the back of my cold pick-up truck. THE QUESTION IS, how do you turn on the brain of this 77 year old man and tell him to get a life?
              My apology to the Moderator and others for my babble.
              Chris

              --- In LX200GPS@yahoogroups.com, "Paul A. Valleli" <valleli@...> wrote:
              >
              > Chris,
              > Point the scope at the Moon or a bright planet or
              > star. Remove the eyepiece and place your eye in its
              > place and look toward the secondary. Any reflections
              > from the draw tube, focuser, or other sources will
              > "knock your eye out". Apply PSA Black Velvet or
              > ultra flat black to the offending areas.
              >
              > Starman Paul
              > ---- Original message ----
              >
              > Date: Mon, 31 Oct 2011 05:34:12 -0000
              > From: "Chris Strang" <chrisstrang@...>
              > Subject: [LX200GPS] Re: Strange reflection (looks
              > like a lissajous figure)
              > To: LX200GPS@yahoogroups.com
              >
              >
              >
              > Thanks Ian for the info, you made my "day"(night)
              > with the good news. I am a serious imager with
              > average-plus skills. I have only seen this problem
              > about 4 times in 3 years and then only with a
              > bright off-axis star using a long exposure,
              > field-flattener, and ZS focuser. I do not think
              > the focuser is the problem, but when the camera is
              > extended well over 4 inches from the F/R the
              > chance of reflections greatly increase. But my
              > reason for the posting was I had popes someone
              > else had solved this problem before. The big plus
              > is that I have met some very interesting people. I
              > am impressed at knowledge base of this group.
              > Thanks again everyone, Chris
              >
              > --- In LX200GPS@yahoogroups.com, "ian matterson"
              > <ian.matterson@> wrote:
              > >
              > > Hi Chris,
              > > the good new is that the corrector plate
              > position is the only one that is critical, the
              > secondary mirror is spherical and just needs to be
              > positioned so that corrections can be made for
              > collimation.
              > > On my lx the top adjustment screw (bobs knobs)
              > is positioned JUST BEFORE 1oclock.
              > >
              > > Have you always had this reflection issue, and
              > how did you workout that the zero shift focuser
              > was causing light path issue's (just curious).
              > > Also its best not to use a F/R when you
              > collimate, start of with a low powered EP and then
              > include a barlow, if you have a guide cam, use
              > that as well, it saves time and effort.
              > >
              > > Good luck tracking down the primary cause of
              > your reflection, I'm sure you will soon, keep us
              > posted with your progress
              > >
              > > Clear1's
              > > Ian Matterson
              > >
              > >
              > >
              > > ----- Original Message -----
              > > From: Chris Strang
              > > Sent: 31/10/11 01:00 AM
              > > To: LX200GPS@yahoogroups.com
              > > Subject: [LX200GPS] Re: Strange reflection
              > (looks like a lissajous figure)
              > >
              > > I believe also it is the camera, but for
              > different reasions. The exposures are over 600 sec
              > so short term vibrations should have a mimimal
              > effect.
              > > I suspect I have more than one problem, but hope
              > it is not the secondary as suggested by Dick. My
              > guess is that I am getting reflections off the
              > exit port and also some off-axis reflections
              > bouncing between the camera chip and the field
              > flattener.The camera is DSLR Canon 450D modified
              > by Hutech.
              > > Thanks for your note.
              > > Chris
              > >
              > > --- In LX200GPS%2540yahoogroups.com , Colin Haig
              > <telescope@> wrote:
              > > >
              > > > Chris - What's the camera ?
              > > > Besides all the suggestions from other folk on
              > eliminating the
              > > > internal reflections, I'm thinking you're
              > using a DSLR, and you
              > > > havent allowed enough time for mirror to
              > settle. If you can, try
              > > > turning on mirror lock up. I suspect the
              > internal reflections are
              > > > getting picked up by mirror motion / vibration
              > until it settles.
              > > > Good luck,
              > > > Colin
              > > >
              > > > At 01:54 AM 2011-10-29, Chris Strang wrote:
              > > > >Does anyone know what is causing lissajous
              > like reflections in my
              > > > >LX200GPS-8? When I am imaging the sky that
              > has a bright star
              > > > >(Alnitak) I at times get strange refiections.
              > Most of the time I am
              > > > >using a field flattener and a Microfocuser
              > which puts the
              > > > >focal-plane back about 4 inches. I don't
              > believe it is caused from dew.
              > > > >See an example from the link below.
              > > > >Chris.
              > > > >
              > > > >
              > > >
              > >http://groups.yahoo.com/group/LX200GPS/photos/album/1108451930/pic/2032870457/view?picmode=&mode=tn&order=ordinal&start=1&count=20&dir=asc
              > > > >
              > > > >
              > > > >
              > > > >
              > > > >------------------------------------
              > > > >
              > > > >Yahoo! Groups Links
              > > > >
              > > > >
              > > > >
              > > >
              > >
              > >
              > >
              > >
              > > [Non-text portions of this message have been
              > removed]
              > >
              >
              >
              >
              >
              > [Non-text portions of this message have been removed]
              >




              [Non-text portions of this message have been removed]
            • Chris Strang
              Thanks everyone, we should take this off line because the technical problem has most likely been solved. If anyone would like to send a note, either as a joke
              Message 6 of 22 , Nov 2, 2011
              • 0 Attachment
                Thanks everyone, we should take this off line because the technical problem has most likely been solved. If anyone would like to send a note, either as a joke or technical info please use chrisstrang@...
                Chris Strang, taylor Michigan, USA
                --- In LX200GPS@yahoogroups.com, larry taborek <taborekle@...> wrote:
                >
                > Chris,
                >  
                > I camp at times and have found these chairs very easy to get in and out of and comfortable enough to sleep in.
                >  
                > http://www.campingworld.com/shopping/item/big-and-tall-harbor-mist-recliner/54592
                >  
                > Larry
                >
                > From: Chris Strang <chrisstrang@...>
                > To: LX200GPS@yahoogroups.com
                > Sent: Monday, October 31, 2011 4:58 PM
                > Subject: [LX200GPS] Re: Strange reflection (looks like a lissajous figure)
                >
                >
                >  
                > Thanks again Starman, I think we may be on to a solution. Now maybe you (or anyone) can solve my other problem being the guru you are. On the said outing, I was 200 miles from home in an open field, no AC, 3:00 AM, ice all over everything, it is 20 deg. F, I am cold and wet, the battery for my dew heaters about dead, and the only place to sleep is in the back of my cold pick-up truck. THE QUESTION IS, how do you turn on the brain of this 77 year old man and tell him to get a life?
                > My apology to the Moderator and others for my babble.
                > Chris
                >
                > --- In LX200GPS@yahoogroups.com, "Paul A. Valleli" <valleli@> wrote:
                > >
                > > Chris,
                > > Point the scope at the Moon or a bright planet or
                > > star. Remove the eyepiece and place your eye in its
                > > place and look toward the secondary. Any reflections
                > > from the draw tube, focuser, or other sources will
                > > "knock your eye out". Apply PSA Black Velvet or
                > > ultra flat black to the offending areas.
                > >
                > > Starman Paul
                > > ---- Original message ----
                > >
                > > Date: Mon, 31 Oct 2011 05:34:12 -0000
                > > From: "Chris Strang" <chrisstrang@>
                > > Subject: [LX200GPS] Re: Strange reflection (looks
                > > like a lissajous figure)
                > > To: LX200GPS@yahoogroups.com
                > >
                > >
                > >
                > > Thanks Ian for the info, you made my "day"(night)
                > > with the good news. I am a serious imager with
                > > average-plus skills. I have only seen this problem
                > > about 4 times in 3 years and then only with a
                > > bright off-axis star using a long exposure,
                > > field-flattener, and ZS focuser. I do not think
                > > the focuser is the problem, but when the camera is
                > > extended well over 4 inches from the F/R the
                > > chance of reflections greatly increase. But my
                > > reason for the posting was I had popes someone
                > > else had solved this problem before. The big plus
                > > is that I have met some very interesting people. I
                > > am impressed at knowledge base of this group.
                > > Thanks again everyone, Chris
                > >
                > > --- In LX200GPS@yahoogroups.com, "ian matterson"
                > > <ian.matterson@> wrote:
                > > >
                > > > Hi Chris,
                > > > the good new is that the corrector plate
                > > position is the only one that is critical, the
                > > secondary mirror is spherical and just needs to be
                > > positioned so that corrections can be made for
                > > collimation.
                > > > On my lx the top adjustment screw (bobs knobs)
                > > is positioned JUST BEFORE 1oclock.
                > > >
                > > > Have you always had this reflection issue, and
                > > how did you workout that the zero shift focuser
                > > was causing light path issue's (just curious).
                > > > Also its best not to use a F/R when you
                > > collimate, start of with a low powered EP and then
                > > include a barlow, if you have a guide cam, use
                > > that as well, it saves time and effort.
                > > >
                > > > Good luck tracking down the primary cause of
                > > your reflection, I'm sure you will soon, keep us
                > > posted with your progress
                > > >
                > > > Clear1's
                > > > Ian Matterson
                > > >
                > > >
                > > >
                > > > ----- Original Message -----
                > > > From: Chris Strang
                > > > Sent: 31/10/11 01:00 AM
                > > > To: LX200GPS@yahoogroups.com
                > > > Subject: [LX200GPS] Re: Strange reflection
                > > (looks like a lissajous figure)
                > > >
                > > > I believe also it is the camera, but for
                > > different reasions. The exposures are over 600 sec
                > > so short term vibrations should have a mimimal
                > > effect.
                > > > I suspect I have more than one problem, but hope
                > > it is not the secondary as suggested by Dick. My
                > > guess is that I am getting reflections off the
                > > exit port and also some off-axis reflections
                > > bouncing between the camera chip and the field
                > > flattener.The camera is DSLR Canon 450D modified
                > > by Hutech.
                > > > Thanks for your note.
                > > > Chris
                > > >
                > > > --- In LX200GPS%2540yahoogroups.com , Colin Haig
                > > <telescope@> wrote:
                > > > >
                > > > > Chris - What's the camera ?
                > > > > Besides all the suggestions from other folk on
                > > eliminating the
                > > > > internal reflections, I'm thinking you're
                > > using a DSLR, and you
                > > > > havent allowed enough time for mirror to
                > > settle. If you can, try
                > > > > turning on mirror lock up. I suspect the
                > > internal reflections are
                > > > > getting picked up by mirror motion / vibration
                > > until it settles.
                > > > > Good luck,
                > > > > Colin
                > > > >
                > > > > At 01:54 AM 2011-10-29, Chris Strang wrote:
                > > > > >Does anyone know what is causing lissajous
                > > like reflections in my
                > > > > >LX200GPS-8? When I am imaging the sky that
                > > has a bright star
                > > > > >(Alnitak) I at times get strange refiections.
                > > Most of the time I am
                > > > > >using a field flattener and a Microfocuser
                > > which puts the
                > > > > >focal-plane back about 4 inches. I don't
                > > believe it is caused from dew.
                > > > > >See an example from the link below.
                > > > > >Chris.
                > > > > >
                > > > > >
                > > > >
                > > >http://groups.yahoo.com/group/LX200GPS/photos/album/1108451930/pic/2032870457/view?picmode=&mode=tn&order=ordinal&start=1&count=20&dir=asc
                > > > > >
                > > > > >
                > > > > >
                > > > > >
                > > > > >------------------------------------
                > > > > >
                > > > > >Yahoo! Groups Links
                > > > > >
                > > > > >
                > > > > >
                > > > >
                > > >
                > > >
                > > >
                > > >
                > > > [Non-text portions of this message have been
                > > removed]
                > > >
                > >
                > >
                > >
                > >
                > > [Non-text portions of this message have been removed]
                > >
                >
                >
                >
                >
                > [Non-text portions of this message have been removed]
                >
              Your message has been successfully submitted and would be delivered to recipients shortly.