8 MM film projector wide angle objective - has forward negative convex lens group and rear positive lens group with bi-concave first lens

摘要

The wide angle objective is for cassette 8 mm film projectors, with which a high focal distance is required. The objective is formed by a front negative lens group (G1) comprising a bi-convex lense (1) and a dispersing meniscus (2), and a rear positive lens group (G2) comprising three individual lenses (3,4,5) and a combined lense (6,7). The first lens (3) in the positive group is bi-concave.