Dual power telescope

Claim 1

A dual power telescope for simultaneously viewing two superposed images of the same object at different magnifications comprising an elongated housing, objective lens means, erector lens means and eyepiece lens means mounted in said housing in optical alignment along a common optical axis, said objective lens means forming an image of the object at the objective focal plane and the image being relayed by said erector leas means to the focal plane of said eyepiece lens means, a Galilean telescope having a convergent objective lens and a divergent ocular lens, said Galilean telescope being positioned on said optical axis between said objective lens means and said erector lens means, with said divergent ocular lens facing said objective lens means and located between said objective lens means and said objective focal plane and with said convergent objective lens facing said erector lens means and located between said erector lens means and said objective focal plane, the diameter of said Galilean telescope lenses being appreciably less than the diameters of said objective lens means and said erector lens means, and appreciably less than the diameter of the image formed at the objective focal plane, thin vane means extending radially inward from said elongated housing and adjustably supporting said Galilean telescope lenses, and external adjusting means connected to said thin vane means for moving at least said convergent objective lens of said Galilean telescope along the optical axis.