A zoom lens includes, in order from an object side to an image side, a
first lens unit having a positive refractive power configured not to move
for zooming, a second lens unit having a negative refractive power
configured to move during zooming, a third lens unit having a positive
refractive power configured to move during zooming, and a fourth lens
unit having a positive refractive power configured not to move for
zooming. The third lens unit includes a positive lens, a negative lens,
and a diffractive optical element. A focal length of the third lens unit
(fc), a focal length of the diffractive optical element (fdoe), a focal
length at a wide angle end of the zoom lens (fW), and a focal length at a
telephoto end of the zoom lens (fT) satisfy the following conditions:
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