Patent ID: 8094385

Claim:
An image pickup lens, comprising: a first lens group including a single negative lens and a single positive lens disposed in order from the object side to the image side and having a positive refracting power; and a second lens group having a positive refracting power; said first lens group and said second lens group being disposed in order from the object side to the image side; said first lens group being fixed, when the image pickup object distance varies from the infinity to the proximity, with respect to an image surface while said second lens group is moved from the image side to the object side to carry out focusing; said image pickup lens satisfying the following conditional expressions (1) to (3): 1.0 <f 2 /fi< 1.5 (1) 1.1 <fi/bfi< 1.5 (2) 0.7 <|f 1 F/f 1 R|< 1.3 (3) where f2: focal length of said second lens group fi: focal length of the entire lens system in an infinitely focused state bfi: back focus of the entire lens system in the infinitely focused state f1F: focal length of said negative lens of said first lens group f1R: focal length of said positive lens of said first lens group.