A zoom lens is disclosed having a zoom ratio larger than four with a field
of view at the short focal length position larger than 85 degrees and
with a minimal number of moving groups. The zoom lens utilizes a compound
zoom structure comprising an NP or NPP zoom kernel followed by a P or PP
zoom relay, with only two or three moving groups that can be used for
both zooming, focusing and athermalization. An overall compact package
size is achieved by the use of prisms to fold the optical path in
strategic locations. An optional variable power liquid cell can provide
close focusing with little or no focus breathing.