Patent ID: 8797646

Claim:
A relay zoom system comprising, in order from an object side: a first lens group having a positive refractive power; and a second lens group having a positive refractive power, wherein the first lens group and the second lens group are each made up of at least two positive lenses and one negative lens, the first lens group and the second lens group move along an optical axis when magnification is varied from a lower magnification edge state to a higher magnification edge state, the first lens group includes: a cemented lens which cements together one of the positive lenses and the negative lens, and a single positive lens, and if fl 1 denotes a focal length of the cemented lens and fl 2 denotes a focal length of the single positive lens, then the relay zoom system satisfies a condition expressed by an expression below: 1 <fl 1 /fl 2<2.