If the image is at infinity, m = D/f For
a compound microscope, the magnifying power is given by m = me × m0
where me = 1 + (D/fe), is the magnification due to the eyepiece and mo
is the magnification produced by the objective Approximately,
o
e
L
D
m
f
f
=
×
where fo and fe are the focal lengths of the objective and eyepiece,
respectively, and L is the distance between their focal points 9