Zoom lens and image pickup apparatus

A zoom lens comprising:

• lens units that consist of, in order from an object side to an image side, a first lens unit having positive refractive power, a second lens unit, and a rear group including a plurality of lens units,
• wherein each distance between adjacent lens units changes during zooming,
• wherein a lens unit disposed closest to an image plane in the zoom lens has negative refractive power,
• wherein, during zooming from a wide-angle end to a telephoto end,
• a distance between the first lens unit and the second lens unit increases and a distance between the second lens unit and the rear group increases, and
• wherein the following inequalities are satisfied:
• 4.4
• ≤
• D
• ⁢
• 2
• ⁢
• t
• /
• D
• ⁢
• 2
• ⁢
• w
• ≤
• 15.
• -
• 2.8
• ≤
• fL
• ⁢
• 1
• /
• fL
• ⁢
• 2
• ≤
• 3.
• where D2w is a distance on an optical axis from a surface closest to an object of the zoom lens to a surface closest to the image plane of the second lens unit at the wide-angle end, D2t is a distance on the optical axis from the surface closest to the object to the surface closest to the image plane of the second lens unit at the telephoto end, fL1 is a focal length of the first lens unit, and fL2 is a focal length of the second lens unit.