Shooting at f/32 and I'm still frustrated with DOF/ Focus

[kevs-2323668]

I have a simple people fine art project. I'm shooting people seated in the studio against a white backdrop with a Sinar 4x5 and a 210 lens.

I was getting one part of their body in focus and the other part out.

So I went from TMY 100 to TMY 400 to increase the F stop from about 11 or 16 or so to f/32.

This last shoot was all shot at f/32, and while it did help in general, still MANY shots are screwed.

I have a subject holding a doll, the subject if tack sharp, yet the doll and even the subjects arm holding the doll (just 6 inches from the sharp subject) is way out of focus.

Or the subject is seated on the floor, and the subject if fully in focus head to toe, but the dolls in front of her are out of focus.

The camera set to zeros, no tilts and shifts. Real frustrated. Any ideas? f/ 32 is not enough?

[BetterSense]

Because fstop is a format-dependent unit, it's really meaningless by itself in terms of DOF. You need to consider what format you are using and approximate magnification (bust, head-shoulders etc.).

F32 on a 210mm lens is about 6.5mm. For a bust-type portrait this size aperture will give you a foor or so of DOF, regardless of film format or focal length. If you are seeing out of focus arms, you must be mis-focusing, your aperture scale is wrong, or something.

[Bill_1856]

http://bobatkins.com/photography/technical/dofcalc.html

[vinny]

Use tilt and/or swing. That's what view cameras are for.

[kevs-2323668]

Thanks Bill, I'm not a big fan of thread responses that send me to long, complex articles. Is there a point or two there I should look for?

Vinny: I never learned tilt/ swing. I assume the tilt/ swings are mostly to put something out of focus — or put a certain plane in focus?

Are you saying at f/32 or even better 6-8 inches should not all be in focus with the camera set to zeros?

[BetterSense]

What we are all saying is that if you want to know DOF, fstop is not enough information. You need to calculate it. F/32 on 4x5 sounds like a small enough aperture for most bust-size-ish portrait to me, so maybe you are focusing wrong, not telling us something, have film flatness issues, or something else.

[David A. Goldfarb]

What's your subject distance? There are many DOF tables and calculators out there on the net and in books, and to know your DOF, you need to know the format, focal length, subject distance (or the distance you're focused at), and the aperture. There's some subjectivity to the result, having to do with what you consider to be acceptible focus for the format you're shooting and amount of enlargment planned, but you can experiment, and if you think your table or calculator is giving you too soft a result at the edges of the DOF range, you can just decide to stop down one more stop than the recommended value.

If your subject is at 6 feet and you are shooting at f:32, you should have about 1'7" of DOF range. If your subject is at 4 feet, you've got about 7", but if you go to f:64, you'll get about 1'3" at the same distance. The calculator I just used to figure that is the one in pCam, an iPhone app with many useful photographic calculations. It also gives you a diagram to help estimate how much distance you have in front and behind the subject within the DOF range for the values supplied.

[Ken Lee]

A 210mm lens is superb for portraits - in terms of angle of view and subject distance - but it doesn't have much depth of field, especially of if you're used to making portraits with smaller format equipment and correspondingly shorter lenses.

When we double the focal length, we need 2 more stops smaller to get the same depth of field.

A 210mm lens at f/22 will have the same depth of field as a 105mm lens at f/11, which is the same as a 50mm lens at f/5.6.

[Michael E]

Let's face it, LF is not the best choice for large DOF at closer distances. You can make your life a lot easier by using a smaller format. Or you choose the points you want in focus and live with a (more or less) blurred rest. If you need face and doll in focus, place your plane of focus accordingly, using the Scheimpflug principle (the google will help you).

Best,

Michael

[Bill_1856]

Thanks Bill, I'm not a big fan of thread responses that send me to long, complex articles. Is there a point or two there I should look for?

Vinny: I never learned tilt/ swing. I assume the tilt/ swings are mostly to put something out of focus — or put a certain plane in focus?

Are you saying at f/32 or even better 6-8 inches should not all be in focus with the camera set to zeros?

You don't have to read the article. Just scroll down to the bottom where the actual table is. Just click on the camera size (4x5), the lens focal length and aperture, and the distance to the subject, and it will give you the depth of field.
My guess is that you are either focusing wrong, have an incorectly registered ground glass, or somebody has taken your lens apart and put it back together wrong.
You're welcome.