Depth of Field Calculator

kingyo

Greetings All,
I take a lot of landscape images and I'm interested in knowing if anyone has come up with a quick and not so dirty method for determining dof (near/far) relative to various focal lengths on the D5200. I'm familiar with the on-line calculators, but I don't wish to use a phone or tablet in the field to view an app. Something like a movable "compass card" giving the various combinations might work well. Or, even a 'cheat sheet' would be nice. I realize there are many factors involved such as focal length, f stop and subject distance as well as CoC factors, etc.

Just thought I'd ask, thanks in advance.

bruto

Here's one that looks as if it might work pretty well:

http://www.photocalcul.com/Calcul/Regles/Notices-regles/notice_samuelson.pdf

There's another one that is very complicated, with a PDF on how to make your own with anodized aluminum!

http://nomographics.com/web/resources/documents/depth_of_field.pdf

The thing you're after is properly called a "nomograph," and you can find an interesting assortment if you do a google search for "Depth of field nomograph" and switch to images.

By the way, although the D5xxx and D3xxx family do not have any proper DOF preview, if you select an aperture before switching to live view, the live view will use that aperture and give you a poor man's DOF preview. Changing in live view will not change it. You must exit live view, change aperture, and then re-enter it. Clumsy but better than nothing at all, I guess.

Some of the specific Nikon lenses have DOF information in their instruction pamphlets. Depending on the lens, you might be able to find some info on the Nikon web site. Remeber that DOF depends on the lens, not the format. You'll get the same DOF on FX or DX.

Edit to add: I was a bit hasty and did not look very carefully at the google search images, most of which seem to be for things other than camera lenses. You're really in luck if you're digging a septic field, but less so if you're trying to get the tree line at the back of the field in focus!

Because DOF is a function of distance, aperture and focal length together, it's pretty complicated to get a full set of figures. Your best bet might be to get sample figures for a few key distances and apertures at a given focal length, and interpolate between them.

kingyo

Thanks very much for the info. Very informative.
FYI, here's a link to a DoF calculator for full frame cameras. Seems well put together and maybe with the correct conversion factor plus a lot of luck it could be useful for the 5200.

bruto

You will get the same depth of field from a crop sensor camera as for a full frame if you use the same lens. Remember, it really is just the equivalent of cropping a full frame image to 75 percent of its dimensions. What's inside that cropped frame is the same whether the sensor size crops it when you take it, or you do it later with scissors.

Actually that's only mostly true, because areas within the depth of field are not actually in focus, only close enough to pass. And what passes depends on several factors, including magnification and pixel size. The traditional marking of DOF scales on lenses, and the calculation of them, assumes that a 35mm image will be magnified five times, giving approximately a 5 x 7 print size. And older lenses could be pretty optimistic even then, assuming relatively soft definition of film and printing. Since a DX image must be magnified a bit more, DOF figures meant for full frame may be a bit generous for DX, and you should probably assume a narrower DOF, especially if you're printing large.

You could experiment a bit if you have a usable DOF calculator for a given lens in full frame. Try it on DX and see. You'll probably do better if you calculate for a stop or two less. So, for example, if you're shooting at f/16, use the DOF figures for f/11 or f/8