Need help with my 75 Schneider lens on a Cambo 4x5

[Ymn]

Hi,

I recently purchased a 75 Schneider lens and am having trouble focusing on my Cambo.. I shoot tabletop set-ups and sculptures that are about 5 feet wide, so basically the camera needs to be about 1 foot from the subject to cover the entire area.

Any suggestions? Should I just stop down to 45 or 64?

thank you for any help!

[BrianShaw]

I, personally, wouldn't use a short lens like that for tabletop photography. You may be making the task even more difficult. But what, exactly, is your focussing probem? I could think of myriad problems associated with using a 75mm on Cambo for that kind of application.

[Ymn]

Thank you for your response. I am only able to focus on objects closer to the lens, while the areas further back, about 3-4 feet from lens, are out of focus. I construct scenes while looking through the focusing screen, so this is an issue. I have used the 90 in the past more successfully, but thought the 75 would work as a wide angle lens..

[E. von Hoegh]

Thank you for your response. I am only able to focus on objects closer to the lens, while the areas further back, about 3-4 feet from lens, are out of focus. I construct scenes while looking through the focusing screen, so this is an issue. I have used the 90 in the past more successfully, but thought the 75 would work as a wide angle lens..

Were I doing tabletop photography of subjects 5 feet wide, I'd be using a 210mm lens. I wouldn't even consider a 75mm lens for such work... If you could describe in more detail what you wish to do, someone can certainly help.

[BrianShaw]

That helps. I thought that perhaps you were having problems getting anything into focus. (I'm not too much of a WA user and find even a 90 to be a challenge on a Cambo... so I can't imagine using a 75!)

If you can get one part of your image into focus, then all you need is Depth of Fiel (DoF) to get the rest in focus. Stopping down would do that but htere may be limits to how much DoF you'll realistically be able ot achieve. A DoF table might help you estimate that, as will stopping down and scrutinizing the ground glass with a loupe. Alternatively, you might be able to get enough DoF in the right planes by using movements.

How deep are your scenes?

[adelorenzo]

Depth of field decreases the closer you move the camera to the subject. One way to get more depth of field would be to use a longer lens, thus keeping the camera farther away.

[ic-racer]

If your front and rear standard wont come closer together you will need a recessed lens board

[Dan Fromm]

The OP has a colossal depth of field problem. Since depth of field is controlled by relative aperture (the dread f/ number) and magnification in the final print, he's stuck. Can't stop down enough, and shouldn't want to, wants his print size. Something has to give, using a longer lens and standing back won't help.

As for using a recessed lens board, the Cambo SC's minimum flange-to-film distance with a flat board, the rear standard reversed on the rail, and the tripod mounting block behind the rear standard is ~ 40 mm. I've measured. A recessed board will give larger movements with a 75 than can be had with a flat board, that's all.

[Bob Salomon]

The OP has a colossal depth of field problem. Since depth of field is controlled by relative aperture (the dread f/ number) and magnification in the final print, he's stuck. Can't stop down enough, and shouldn't want to, wants his print size. Something has to give, using a longer lens and standing back won't help.

As for using a recessed lens board, the Cambo SC's minimum flange-to-film distance with a flat board, the rear standard reversed on the rail, and the tripod mounting block behind the rear standard is ~ 40 mm. I've measured. A recessed board will give larger movements with a 75 than can be had with a flat board, that's all.

I disagree. What he has are two problems, the plane of sharp focus and then a depth of field problem.

With tilts he can control the plane of focus. By focusing on the correct spot and stopping down he can control his depth of field. Should be OK at 22.

But he has other problems, a wide angle lens is simply not corrected for this type of work and taking it so far out of its optimal range will create other problems. And if stopping down beyond 22 will result in diffraction. Lastly this lens, and the 90 and any other short focal length will greatly forshorten the subject resulting in parts of the scene closer to the lens being reproduced much larger in proportion then objects further away. If this is what is desired, then fine. If not, back off and go to at least a 210 as others have suggested.