PURPOSE: To obtain a titled lens which is extremely small in a variation of distortion in a wide photographing area by constituting it of three lens groups having positive, positive and negative refractive powers in order from an object side, and satisfying a prescribed condition.

CONSTITUTION: A titled lens consists of the first lens group I having a positive refractive power, the second lens group II having a positive refractive power, and the third lens group III having a negative refractive power in order from an object side. In case of focusing to an adjacent object from an infinity object, both an air interval between the first and the second lens groups I , II, and an air interval between the second and the third lens groups II, III are increased, and also conditions of formulas I WIII are satisfied. In this regard, in the formulas, (f):f2, f3: and ΔdA, ΔdB denote a focal distance of the whole system, each focal distance of the second and the third lens groups II, III, and each variation quantity of the air intervals between the first and the second lens groups I , II, and between the second and the third lens groups II, III, respectively.