<Dd> D O F = 2 H s (s − f) H 2 − (s − f) 2 for s <H and H = f 2 N c . (\ displaystyle \ mathrm (DOF) = (\ frac (2Hs (s-f)) (H ^ (2) - (s-f) ^ (2))) (\ text (for)) s <H (\ text (and)) H = (\ frac (f ^ (2)) (Nc)) \, .) </Dd> <P> Magnification m (\ displaystyle m) can be expressed as </P> <Dl> <Dd> m = f (s − f); (\ displaystyle m = (\ frac (f) (\ left (s-f \ right))) \,;) </Dd> </Dl> <Dd> m = f (s − f); (\ displaystyle m = (\ frac (f) (\ left (s-f \ right))) \,;) </Dd>

What is the purpose of depth of field