front tilt/hyper focal distancegreenspun.com : LUSENET : Large format photography : One Thread |
"You are better off using front or rear tilt. "in a posting regarding hyper focal distance, the use of front/rear tilt was mentioned as a corrective measure. i am not familiar with this and was wondering if some one would like to comment on it.
robert
-- robert charles (robertcharles51@hotmail.com), April 27, 2002
Robert,Tilting the front or rear standard will change the plane of focus according to the Scheimpflug principle:
http://www.trenholm.org/hmmerk/HMbooks3.html http://www.trenholm.org/hmmerk/SHSPAT.pdf http://www.trenholm.org/hmmerk/HMbook18.html
-- Ake Vinberg (ake@vinberg.nu), April 27, 2002.
I did not see the original post, but assume we are talking about large format. The question is somewhere between "what is the meaning of life" and "how are babies made." But the best short answer is the illustration on the instructions for the Rodenstock DOF & Tilt calculator. I have a bmp file of it that I'll e-mail to you.You going to need to read a book on large format. The bad news is that all the books I have ever seen are deficient in dealing with whole Scheimpflug subject. These books do not explain enough but they will get you started.
Tilt is the main attribute most photographers would list as the reason they put up with large format in the first place.
-- John Hennessy (northbayassociates@earthlink.net), April 27, 2002.
to clarify: i'm working with 4x5 format..(linhof tech III) thanks for the comments..robt
-- robt (robertcharles51@hotmail.com), April 27, 2002.
Generally speaking:Use the rear swings / tilt to control perspective; use front swings / tilt to control focus. Or use a combination of both to get the perspective you want while holding the focus.
-- Per Volquartz (volquartz@volquartz.com), April 27, 2002.
Hperfocal distances are used to maximize depth of field when the position of a lens is fixed in relation to the camera back/film plane, which is the case with almost all 35mm/medium format camera/lens combinations. Lenses on view cameras aren't fixed in relation to the camera back/film plane and instead can be tilted or swung to change the plane of focus and facilitate getting everything sharp from the nearest object in the scene to the farthest object. So you often don't need to mess around with hyperfocal distance tables, figuring out how far into the scene you should focus, etc. etc. with a view camera. Instead, in the common situation where a photographer is attempting to get everything from the nearest point in the scene to the farthest point in focus, the front standard is slightly tilted forward and you can look at the ground glass to see what is sharp and what isn't, then tilt some more if necessary until everything that you want to appear sharp looks sharp on the ground glass. That's a very rudimentary explanation and it doesn't work with all situations but it's basically accurate. Unfortunately your Tech III camera doesn't have forward tilt on the front standard so you may still need to rely on hyperfocal distances, though you can achieve much the same effect by tilting the back backwards. That's something of a pain with the Technika cameras because of all the loosening and tightening of knobs that you have to do in order to move the back. Also, tilting the back backwards will change the shape of objects in the foreground but often this isn't objectionable and sometimes is even desirable.
-- Brian Ellis (bellis60@earthlink.net), April 28, 2002.
If he can't tilt the front standard, he can do the following.... Using the tripod head, tilt the entire camera forward. Then use front rise or fall to re-center. Finally, use rear tilt to get the needed depth. It's not as convenient but will give the same result.
-- Steve Gangi (sgangi@hotmail.com), April 28, 2002.