Variable magnification camera objective - with displacement of rear lens controlled by cam at rear of front lens mounting

摘要

The objective uses at least lenses (L1, L2, L3) which more in conjunction with one another, but by differing amounts, the setting ring (1) for the objective acts as the mounting for the front lens (L1, L2) and has a cam curve (2) at the rear defining the movement of the rear lens (23). The mounting (6) for the rear lens (L3) has a campin (4) contacting this cam curve (2) with a further guide pin (8) at the rear of the mounting (6) fitting behind a shoulder of a frame ring (10) which is screwed to the setting ring (1). The rotation of the latter causes rotation of the first lens (L1, L2) and linear movement of the second lens (L3).