Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,002   Posts: 1,524,459   Online: 1046
      
Page 1 of 2 12 LastLast
Results 1 to 10 of 16

Thread: A quickie.....

  1. #1
    scootermm's Avatar
    Join Date
    Jun 2004
    Location
    Austin, TX
    Shooter
    ULarge Format
    Posts
    1,867
    Images
    235

    A quickie.....

    this will likely be a quick answer but Im gonna ask it even though it may be something basic that I should already know the answer too.....

    why are the corners clipped on groundglass?

  2. #2
    jd callow's Avatar
    Join Date
    Jan 2003
    Location
    Milan
    Shooter
    Multi Format
    Posts
    8,002
    Images
    117
    I was under the assumption that it was to allow for air flow.

    *

  3. #3
    Silverpixels5's Avatar
    Join Date
    Mar 2003
    Location
    Houston, TX
    Shooter
    Multi Format
    Posts
    594
    Images
    15
    i believe its to check the coverage of your lens. It also makes extending the bellows easier.
    RL Foley

  4. #4
    Flotsam's Avatar
    Join Date
    Sep 2002
    Location
    S.E. New York State
    Posts
    3,221
    Images
    13
    To allow air to escape/enter when compressing/extending the bellows?
    That is called grain. It is supposed to be there.
    =Neal W.=

  5. #5
    scootermm's Avatar
    Join Date
    Jun 2004
    Location
    Austin, TX
    Shooter
    ULarge Format
    Posts
    1,867
    Images
    235
    Quote Originally Posted by Silverpixels5
    i believe its to check the coverage of your lens. It also makes extending the bellows easier.

    okay see this is what confuses me...... for some reason Ive found it harder to check for vignetting with the clipped corners. causes weird shadows from the clipped corner etc.... maybe Im doing something wrong.

  6. #6

    Join Date
    Feb 2004
    Location
    Iowa
    Shooter
    Multi Format
    Posts
    829
    Images
    7

  7. #7

    Join Date
    Sep 2002
    Location
    Knoxville, TN
    Shooter
    Multi Format
    Posts
    453
    Clipped corners serve 2 functions. It lets air in and out when you move the standards with a lens mounted, and it allows you to see if there is mechanical vignetting from a lens.

    For example, if I mount a 110 SS XL on my 8x10, then look at the aperture through the clipped corners, I see an oval until I stop the lens down a bit. The aperture is oval and not round because at wide apertures, the rear lens cell barrel obscures part of the aperture. You don't want to take a picture this way, so you look through the clipped corners to determine at what f-stop setting you can see the entire aperture.

    Steve

  8. #8

    Join Date
    Sep 2002
    Shooter
    Large Format
    Posts
    4,530
    Quote Originally Posted by scootermm
    okay see this is what confuses me...... for some reason Ive found it harder to check for vignetting with the clipped corners. causes weird shadows from the clipped corner etc.... maybe Im doing something wrong.
    You have to look from the front through the lens, if you can see all four corners you have no vignetting.

  9. #9

    Join Date
    Feb 2004
    Location
    Iowa
    Shooter
    Multi Format
    Posts
    829
    Images
    7
    Quote Originally Posted by Jorge
    You have to look from the front through the lens, if you can see all four corners you have no vignetting.
    It makes sense to me that this method would work without clipped corners as well. Is that correct?

  10. #10
    jimgalli's Avatar
    Join Date
    Sep 2002
    Location
    Tonopah Nevada
    Shooter
    ULarge Format
    Posts
    3,401
    Blog Entries
    2
    Images
    155
    I've been doing HABS/HAER work for the company I work for with "their" camera which is a Cambo with a 210, 150, and a 6.8 Grandagon 90. The 90 gets used for 100% of the interior things and is constantly strained to the maximum rise / shift etc. I'd be lost without the corner cut-outs to tell me if I've passed the edge of the image circle.

Page 1 of 2 12 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin