A real image type zoom finder that, albeit being reduced in size and
thickness, can gain high enough zoom ratios and an imaging system
equipped with such a real image type zoom finder. The real image type
zoom finder comprises an objective optical system, an image-erection
optical system and an eyepiece optical system. The objective optical
system comprises a negative first lens group, a positive second lens
group, a negative third lens group and a positive fourth lens group. Upon
zooming, the first lens group and the fourth lens group remain fixed, the
second lens group moves toward the object side at the telephoto, not the
wide-angle end, and the third lens group moves toward the image side at
the telephoto, not the wide-angle end. The first lens group consists of
one single lens of double-concave shape, and that single lens satisfies
condition regarding a shape factor.