PURPOSE: To satisfy specifications of a zooming ratio of three times, by which a focal distance and brightness extend from 35mmF3.5 at a wide angle side to 105mmF4.5 at a telephoto side, by constituting 16 pieces of single lenses of four groups, and satisfying various conditions of specified expressions.

CONSTITUTION: G1 is a negative meniscus lens whose concave face is turned to an image side, G2 is a positive lens, G3 is a positive meniscus lens whose convex face is turned to an object side, G4 is a negative meniscus lens whose concave face is turned to the image side, G5 is a positive meniscus lens whose convex face is turned to the image side, G6 is a negative lens, G7 is a positive meniscus lens whose convex face is turned to the object side, G6 and G7 are cemented composite negative lenses, and G8 consists of a positive meniscus lens whose convex face is turned to the object side. G9 and G10 are positive lenses, G11 is a negative lens whose concave face is turned to the object side, G12 and G13 are positive lenses, G14 is a negative lens, and G15 and G16 are constituted of positive meniscus lenses whose conves faces are turned to the image side and the object side, respectively. Variable magnification and focusing can be executed by a relation movement of the first, the third and the fourth lens groups, and a single movement of the first lens groups, respectively, also various conditions of a specified expression are satisfied, and a zooming ratio of three times is satisfied in a range where a focal distance and brightness extend from 35mmF3.5 at a wide angle side to 105mmF4.5 at a telephoto side.