Does anyone have a ROT for DOF?

[Steven Kersting]

In a critique of one of my pictures I received the tip to "focus down the bill some" to make the most of the 1/3 2/3 DOF and get both a long bill and eye in focus w/ shallow DOF.
Makes perfect sense. But I never really know what my DOF is going to be. I understand aperture and working distance and how they interact w/ DOF and I have a VERY rough idea of what I'm going to get...but that's it.

I don't chimp enough I guess. The DOF button is useless to me, I just can't see it (I have mine assigned to spot meter). And I don't tend to "play with it" enough when the opportunity affords itself.....I'll have to fix that.

I have ROT for all sorts of things; fov/focal length, hyperfocal distance, etc. But w/ DOF it's a bit of "luck of the draw".

Anyways, unless someone's got something to help I'll probably have to stick w/ focusing on the eye (unless it's a very still subject and I have time to "play with it").

[Arthur Morris]

For 28 years I have been focusing on the eye and letting the d-o-f fall where it may.... The only time I worry about it is when I am working very close. Then I try to stop down a bit. I never use the preview either so you are in good company there :)

[Jeff Donald]

The 1/3 DoF in front of focus point and 2/3 DoF behind focus point is a myth that is often perpetuated. Check out any DoF calculator (http://www.dofmaster.com/dofjs.html) and you'll see that DoF is often 50/50, 40/60, 30/70 and NOT 33/67.

[Jim Neiger]

I have sort of a target aperture for most situations, but when the light gets low I usualy sacrifice DOF before anything else. My ROT apertures are based on camera crop factor and are as follows:

1.0 - F8
1.3 - F7.1
1.6 - F5.6
1.5 - F5.6

These are just general ROTs when the light is plentiful. There are many situations where I would deviate from these ROTs.

[paul leverington]

What's Rot?

[Mike Tracy]

What's Rot?

Rule of thumb.

[paul leverington]

Oh--ok --thanks Mike.

Steve you should make up a little chart or something maybe for your more commonly used aperatures. That online calculator works pretty easy. Just plug in what you got and what your doing. Generally it's a 50-50 split for the longer glass I believe.

I have been playing with changing my calibration(up to 12 clicks in some cases) to better use all the DOF available with tremendous success. But this is not practical in fast changing situations. But when light is low and your at your limits it gives you lots more DOF to play with.

Paul

[Dave Leroy]

Good to hear Paul.

I had wondered about that option.

Dave

[Arthur Morris]

I have sort of a target aperture for most situations, but when the light gets low I usualy sacrifice DOF before anything else. My ROT apertures are based on camera crop factor and are as follows:

1.0 - F8
1.3 - F7.1
1.6 - F5.6
1.5 - F5.6

These are just general ROTs when the light is plentiful. There are many situations where I would deviate from these ROTs.

When did you ever use a camera with a 1.5 crop factor ? :)

[Jim Neiger]

When did you ever use a camera with a 1.5 crop factor ? :)

Whenever I trade for a while with a customer that has a Nikon with a 1.5 crop factor. People on the dark side often want to try my Canon rig, so I trade with them for a while and let them experience the joys of Canon while I sample the dark side. :bg3:

[Arthur Morris]

Thanks Jim. I cannot do that...