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Thread: Stop Down or Use Tilt for DOF

  1. #1

    Join Date
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    Corpus Christi and Hallettsville, Texas, USA
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    Stop Down or Use Tilt for DOF

    Hi All,
    My question is about the best technique to get adequate depth-of-field without losing adequate sharpness. I have been stopping down to about f/45 recently. My DOF app tells me I should have adequate DOF but there is a fuzziness about my images. It could be shake from a low shutter speed. (It seems I am often shooting leaves and tall grass in wind). I do have a what I think is a decent Benro tripod. But I wonder about diffraction at f/45. I have a Schneider APO Symmar 210/5.5 and a Fujinar W 150/6.3.

    For example:
    If I was using the 150mm at f/45 focused at 20 feet, I should be in focus from about 9 feet to infinity. I guess it would be better to use a slightly wider aperture and a little front tilt to minimize diffraction, but I am still practicing getting near and far in focus using front tilt. I just bought 2 fresnels and hope that helps focusing. I do have a nice old Nikon 7x lupe. I presently have a Calumet C403, but have a 4x5 Intrepid on order.

    So how do you'all manage the combination of tilt and stopping down to get the wanted DOF with minimizing the effects of diffraction (if diffraction is really an issue)? I would think keeping the lens at f/16-f/22 would be optimum.

    Thanks in advance,
    Steve Pituch (In the middle of TS Harvey)

  2. #2
    Silver Fox
    Join Date
    Sep 2003
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    Ann Arbor, MI
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    Re: Stop Down or Use Tilt for DOF

    See in the Home Page "How to Focus the Camera," and "How to Select the f-Stop." I found both very helpful.
    Peter Collins

    "Growing older is not for sissies." --anon.

  3. #3

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    Corpus Christi and Hallettsville, Texas, USA
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    Re: Stop Down or Use Tilt for DOF

    Thank you Peter. Sorry for the duplicate thread. My internet is not responsive during TS Harvey. Can't seem to delete the other thread.
    Steve

  4. #4

    Join Date
    Sep 1998
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    10,357

    Re: Stop Down or Use Tilt for DOF

    Tilts and swings do not control depth of field. They modify the plane of sharp focus. Stopping the lens down controls depth of field.
    The first thing you need to do is to learn where to focus the camera to maximize your depth of field. Focusing at the correct distance and then stopping down to maximize the depth of field and using your camera movements to control the plane of sharp focus will ensure that what you want to be sharp is sharp. Of course you should not stop so far down that you create diffraction. That means that for most lenses on 45 that you shoot at optimal aperture which is usually 22. At 45 you are in diffraction.
    A simple way to get what you want sharp and use the correct amount of camera movements us to use the Rodenstock pocket DOF/Scheimpflug calculator. Camera tilts and swings are the Scheimpflug movements.

  5. #5

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    Re: Stop Down or Use Tilt for DOF

    Bob,

    Found it online. Can that be used with any LF camera..such as a field camera?
    Or does it need to have scales to transfer the info ?

    Thanks,

    Serge

    Quote Originally Posted by Bob Salomon View Post
    Tilts and swings do not control depth of field. They modify the plane of sharp focus. Stopping the lens down controls depth of field.
    The first thing you need to do is to learn where to focus the camera to maximize your depth of field. Focusing at the correct distance and then stopping down to maximize the depth of field and using your camera movements to control the plane of sharp focus will ensure that what you want to be sharp is sharp. Of course you should not stop so far down that you create diffraction. That means that for most lenses on 45 that you shoot at optimal aperture which is usually 22. At 45 you are in diffraction.
    A simple way to get what you want sharp and use the correct amount of camera movements us to use the Rodenstock pocket DOF/Scheimpflug calculator. Camera tilts and swings are the Scheimpflug movements.

  6. #6

    Join Date
    Dec 2006
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    Hamilton, Canada
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    1,378

    Re: Stop Down or Use Tilt for DOF

    Regarding diffraction, I am reminded of Weston's Pepper number 30 shot at f 256.
    https://petapixel.com/2017/08/15/fam...exposure-f240/
    Imagine how much sharper it could have been if it had not been ruined by diffraction!

    Click image for larger version. 

Name:	pepper 30.jpg 
Views:	85 
Size:	38.3 KB 
ID:	168851
    Bill
    "There are a great many things I am in doubt about at the moment, and I should consider myself favoured if you would kindly enlighten me. Signed, Doubtful, off to Canada." (BJP 1914).

  7. #7

    Join Date
    Sep 1998
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    10,357

    Re: Stop Down or Use Tilt for DOF

    Quote Originally Posted by Serge S View Post
    Bob,

    Found it online. Can that be used with any LF camera..such as a field camera?
    Or does it need to have scales to transfer the info ?

    Thanks,

    Serge
    It works for any camera from 35 to 810.

  8. #8

    Join Date
    Sep 1998
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    10,357

    Re: Stop Down or Use Tilt for DOF

    Quote Originally Posted by cowanw View Post
    Regarding diffraction, I am reminded of Weston's Pepper number 30 shot at f 256.
    https://petapixel.com/2017/08/15/fam...exposure-f240/
    Imagine how much sharper it could have been if it had not been ruined by diffraction!

    Click image for larger version. 

Name:	pepper 30.jpg 
Views:	85 
Size:	38.3 KB 
ID:	168851
    And everything is in the center against a black background. Is that what you will shoot?

  9. #9

    Join Date
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    Re: Stop Down or Use Tilt for DOF

    Can you elaborate that. Does that mean diffraction only occurs in the corners of the view? I always understood that diffraction affected the entire image.
    Bill
    "There are a great many things I am in doubt about at the moment, and I should consider myself favoured if you would kindly enlighten me. Signed, Doubtful, off to Canada." (BJP 1914).

  10. #10

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    Re: Stop Down or Use Tilt for DOF

    Quote Originally Posted by Bob Salomon View Post
    And everything is in the center against a black background. Is that what you will shoot?
    I'm saying that that type of image, other then not being critically sharp as with today's lenses would not show you diffraction unless you had the same image shot at 22 and normal exposure times. This is an art print to satisfy his requirements.

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