Still life - DOF problem

[Chester McCheeserton]

Bob, the 1/3d rule doesn't apply close up. It also doesn't apply at infinity.

Why doesn't 1/3 rule apply close up? Or at infinity?

[Chester McCheeserton]

I always found diffraction on film highly overrated, If your goal is to make a contact print, I'd guestimate 1/3 of the way from the closest flower to the wall and stop down to F64.

If enlarging, I'd back up, focus on the same spot, shoot it at F32 and crop. Or get a 210 lens.

[Chester McCheeserton]

Focus 1/3 to halfway in, tilt if it helps, and shoot stopped down with fingers crossed.
Me, I’d focus stack with my medium format digital tech gear and be done with it.

+ 1 or even with a full frame small sensor.

[Dan Fromm]

Why doesn't 1/3 rule apply close up? Or at infinity?

That's how the calculations come out. Do them.

Oh, and by the way, one third of infinity is infinity.

[Tin Can]

and beyond

[Pere Casals]

First image focus on the frame, the second image focus on the flowers

Use this DOF calculator, it makes a good calculation of the theoric circle of confusion with different settings. Using it a bit you will get a clear idea on how "Focus management" is optimized.




Anyway each lens has a particular behaviour in the DOF, there is a graph named Through Focus MTF that plots the "blur level" through the depth, some proficient cinematographers use those graphs to understand how a particular lens works.

http://cinematechnic.com/optics/super-baltar

[ic-racer]

https://www.largeformatphotography.info/fstop.html

[Drew Bedo]

Sure, measure and calculate . . .its all good.

But check it out on the ground glass. I took a workshop at Santa Fe3 years ago (mid-1990s) and one thing really stuck with me. /the instructor said to us, "The ground glass is truth." and "If you don't see it there, it isn't there."

So check it out. I use a set of bar codes to check focus in diffident spots of a composition. Stopping down haqrd does make it dim. I turn on extra hot lights to let me see what-is-what , then turn them off to expose with strobes or natural light.

I guess what I am saying is use all the tools and techniques you have.

[Jody_S]

I use a set of bar codes to check focus in diffident spots of a composition. Stopping down hard does make it dim.

I've found LED flashlights work well when you have to do this stopped down or with an f16 lens indoors. The ones with 5-6 individual LEDs, if you can make out each individual LED on the ground glass then it's in focus.

[C. D. Keth]

I've found LED flashlights work well when you have to do this stopped down or with an f16 lens indoors. The ones with 5-6 individual LEDs, if you can make out each individual LED on the ground glass then it's in focus.

The small size maglites work well, too, the ones with a regular incandescent bulb. You can unscrew the lens and set the flashlight into the lens housing so the whole thing stands up like candle.


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