Zoom lens having a light weight and temperature independent fourth lens group

A zoom lens comprising:

• a first lens group having a positive refracting power, said first lens group consisting of two lens elements arranged along a common optical axis;
• a second lens group having a negative refracting power;
• a third lens group having a positive refracting power, said third lens group consisting of two lens elements arranged along said optical axis;
• and
• a fourth lens group having a positive refracting power;
• said first, second, third, and fourth lens groups being successively arranged along said optical axis in the order named from an object side, said first and third lens groups being fixed in position, said second lens group being movable for varying a magnification, and said fourth lens group being movable for compensating for an image plane movement due to the varied magnification and also for focusing;
• wherein said fourth lens group consists of a negative-meniscus lens element having a convex surface directed toward the object side and a positive lens element, said negative-meniscus lens element and said positive lens element being successively arranged along said optical axis in the order named from the object side, and at least one of said negative-meniscus lens element or said positive lens element being made of a synthetic resin.