[breadwinner]

How is this different from using a small aperture size?

When you reduce aperture size the depth of field increases. So for example when you use f/16 pretty much everything from a few feet to infinity is in focus.

[oxw]

Very small apertures reduce image quality due to diffraction, which this avoids

Last page in the paper has a comparison between their approach and f/32 https://imaging.cs.cmu.edu/svaf/static/pdfs/Spatially_Varyin...

[malfist]

Is that actually true? I do astrophotography through an f/10 telescope and its focus is very sensitive. I use a focuser that moves the camera 0.04 microns per step.

Not doubting you, just asking to understand. Astrophotography doesn't always behave the same as terrestrial photography

[ruined]

in addition to aperture, percieved depth of field greatly depends on:

- focal length (wider is deeper)

- crop factor (higher is deeper)

- subject distance (farther is deeper)

compared to your telescope, any terrestrial photography is likely at the opposite extremes, and at a disadvantage everywhere but subject distance.

but, focus is most mechanically sensitive near infinity. adjustment creates an asymptotically larger change in the focal plane as infinity is approached.

in a point-and-shoot camera with a wide lens at f16, "infinity" basically means across the street.