Zoom lens, extender lens, and imaging apparatus

A zoom lens having, in order from an object side, a focusing unit including a focusing lens group moving for focusing, a variable magnification unit including at least two variable magnification lens groups moving while changing a mutual interval for variable magnification, an aperture stop, and an image forming unit including an image forming lens group,

• wherein the image forming unit consists of an M1 lens group, an M2N lens group, and an M3 lens group in order from the object side,
• the M2N lens group is replaceable with an M2E lens group that enlarges an image forming magnification,
• in a case where an Abbe number of a positive lens of the M2E lens group is νd1, an average value of temperature change coefficients from 0° C. to 40° C. of a refractive index with respect to d line in the air is dn/dt, and dn/dt of the positive lens of the M2E lens group is dn/dt1, the M2E lens group comprises at least one positive lens satisfying conditional expressions (1) and (2), and
• 55<νd1 (1)
• 5.5<dn/dt1<10 (2)
• in a case where an average value of dn/dt of the positive lenses of the M2E lens group is dn/dt_ave_P, and an average value of dn/dt of negative lenses of the M2E lens group is dn/dt_ave_N, conditional expressions (3) and (4) are satisfied.
• 3.5<dn/dt_ave_P<6 (3)
• 1.5<dn/dt_ave_N<6 (4)