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  1. #1
    RePete's Avatar
    RePete Guest

    Default DLR in C5 prime focus: cannot get fully in-focus images



    When attaching our new Canon 350D SLR to the prime focus
    of our little C5, we cannot obtain the sharpness that the
    camera viewfinder (SLR) shows us.
    Even though using lock-mirror, 2-10 sec. (remote) self-timer
    and exposure times of 50th of a second and faster,
    images taken are way to blurry (daytime).
    Goddammit. What are we doing wrong ?
    Reg. Pete J.



  2. #2
    Rich's Avatar
    Rich Guest

    Default DLR in C5 prime focus: cannot get fully in-focus images


    RePete wrote:

    If you consider the shutter slap on those cheap entry-level cameras can
    produce noticeable
    blur at 1/15th to 1/30th of a second hand held, is it so difficult to
    imagine blurring with a 1250mm focal length lens at 1/50th or faster?
    Use a high ISO and a shutter speed of 1/1000
    on a sunny day and see if the blur goes away. If not, you are doing
    something else wrong, like shooting through heat waves.


  3. #3
    Joe Ringer's Avatar
    Joe Ringer Guest

    Default DLR in C5 prime focus: cannot get fully in-focus images

    You wrote:


    Do you wear glasses, if so focus with them on.

    Joe




  4. #4
    George's Avatar
    George Guest

    Default DLR in C5 prime focus: cannot get fully in-focus images


    "RePete" <cay@yahoo.com> wrote in message
    news:newscache$934w7j$vcf$1@news.webpartner.dk...

    You can make a mask out of construction paper the fits over the end of your
    c5. The mask would have three holes cut out of them (about 1/2 inch in
    diameter). When you place the mask over the end of the scope, look through
    the viewfinder, and adjust the focus until the images of the three holes
    line up to make one perfectly focused circle. Then take the mask off and
    take your picture.

    George



  5. #5
    Sam Wormley's Avatar
    Sam Wormley Guest

    Default DLR in C5 prime focus: cannot get fully in-focus images

    Joe Ringer wrote:

    C5s have very poor stability for astro-photography. Even the shutter
    will vibrate the setup... get out the sandbags. Try leaving the shutter
    open and using a black card to start and stop exposures... at least the
    longer ones.


  6. #6
    nytecam's Avatar
    nytecam Guest

    Default DLR in C5 prime focus: cannot get fully in-focus images


    Rich Wrote:

    Rich - What's with the -cheap entry-level cameras- stuff for Canon 350
    - the problem is Internet gurus with a - very small g- !!


    --
    nytecam

  7. #7
    spectre180's Avatar
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    With prime focus, in daytime, I would assume that the same holds true for your scope as it does for lenses with the camera, in that your shutter speed needs to be the same or faster than your focal length. If you have a 500mm lens attached, then your shutter speed needs to be 1/500 sec or faster, this would alleviate the blur.
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  9. #8
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