Depends on where you focus. And how wide the angle of the lens is.

If you focus at infinity, everything from about 20 feet in front of you to infinity will be in focus with most "normal" lenses.

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Vi veri universum vivus vici.
(Si hoc legere scis nimium eruditionis habes.)

Say I am using a 50mm f/1.8, and I am standing at the edge of the Grand Canyon. If I focus out to infinity, what would look different (DOF wise) than if I had a zoom lens set at 50mm but f/22?

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An eye for an eye makes the whole world blind.

Almost no difference. The f22 would be slightly softer due to diffraction... and f1.8 would have slight vignetting - just due to being open that wide.

The DoF differences would only be apparent on subjects very close to you. Which, standing at the edge of the Grand Canyon, is nothing.

If - however, you were focused at say, 10 feet. The F1.8 would be pretty out of focus at the horizon (and other side), but the f22 would still be passably sharp.

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Vi veri universum vivus vici.
(Si hoc legere scis nimium eruditionis habes.)

Exactly what I assumed, thanks for the confirmation.

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An eye for an eye makes the whole world blind.

You guys are forgetting 1 thing.

F22 isn't the sharpest a lens can be set to. If you use F22, it only means that you got more depth in a photo.

Each lens got his on most sharpest F-value. This is duo the physical build limitation of lenses.

According to the MTF chart here : [link] the sharpest photo you get with F 5.6. So I would set it to F 5.6

According to [link] when the 50mm is set to F5.6 (on a Canon 400D), the Hyperfocal Distance is 23.3 m then. So that means that everything beyond 23.3m will be crispy sharp.

I love lens-science

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<sub>- IR: [link]
- Night: [link]
- Macro: [link]</sub>

Playing with [link] the hyperfocal distance is 242 feet. Focusing at this distance has everything from 121 feet to infinity in acceptable focus.

If you focus at infinity, everything from the hyperfocal to infinity will be in acceptable sharpness.

If you are at f/5.6, the hyperfocal distance is 76.5 feet.

If you are after the sharpest image, there is a trade off between diffraction (gets worse as you stop down) and aberrations in the lens itself. As you stop down, you use the center of the lens which is sharper.

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Michael (shagie)

nobody forgot that - both shagie and I mentioned diffraction and other abberations.

And the OP's question did not say anything about sharpness - only what was "in focus"

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Vi veri universum vivus vici.
(Si hoc legere scis nimium eruditionis habes.)