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.
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
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.
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.