| 摘要 |
PROBLEM TO BE SOLVED: To obtain a wide angle lens whose viewing angle is wide as a photographing viewing angle is 100 deg., the occurrence of color shading is suppressed by separating an exit pupil position and the back focus is long enough to arrange a three-color resolving optical system and is five times for a focal distance in a retrofocus type wide angle lens. SOLUTION: This is a wide angle lens whose back focus is long, where a first lens group G1 consisting of a 1a-th negative lens group G1a and a 1b-th positive lens group G1b and having negative refracting power and a second lens group G2 having positive refracting power are arrayed from an object side and which satisfies expressions [I] and [II]. The expression [I] is 5.0<Bf/(f), the expression [II] is -0.05<tanθ<0.05 and provided that, (f) means the focal distance of all system, Bf means the back focus of all system,θmeans an angle formed by the main light beam facing to a screen corner part and an optical axis.
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