Patent ID: 7880797

Claim:
A tilt lens system comprising: a focus lens unit being movable during focusing a diaphragm sharing a primary optical axis with the focus lens unit at the center of the diaphragm and being arranged with or within the focus lens unit; and a tilt lens unit having a negative refractive power and having an optical axis capable of being tilted with respect to the primary optical axis, wherein the tilt lens unit is arranged on an image side of the focus lens unit and the diaphragm, and wherein Conditional Expressions (1) and (2) are satisfied as follows, 1.3<βt<1.7 (1) 0<P<H1 (2) where βt is a lateral magnification of the tilt lens unit when the optical axis is not tilted, P is a distance from a most object side surface of the tilt lens unit to a rotating center of the tilt lens unit when the optical axis of the tilt lens unit is tilted, and H 1 is a distance from the most object side surface of the tilt lens unit to a first principal point of the tilt lens unit.