Carl-zeiss-stiftung

Dieter Rossmann

Volker Donn

Christian Ludwig

A zoom lens mount in which all adjustments for variation of focal length and for focusing at all focal lengths as well as marco-focusing can be accomplished by manipulation of a single external operating ring. Movements are smooth from one position to another, eliminating or reducing the danger of jamming which has occurred with some prior constructions. Focal length is adjusted by axial displacement of the operating ring, and focusing by rotation of the operating ring. In the wide-angle position, marco-focusing can also be accomplished with the same operating ring.

Zoom lens mount

A focusing system for long focal length objectives, having an intermediate tube between the camera and the objective proper. For purposes of focusing, there is a displaceable part movable longitudinally through the intermediate tube, and movement of this part serves to move the lens elements axially for focusing. A receiver portion on the bottom of the intermediate tube receives interchangeably, in quickly attachable and detachable manner, either one of two different focusing mechanisms, the first having the shape of a gun stock with a trigger-like member serving to focus the lens quickly but not necessarily precisely when quick picture shooting of moving objects is desired, the second mechanism having means for accurate focusing and a tripod thread socket. Provision is made for turning the camera 90 degrees to change the format of the picture. Mechanism is provided for pre-setting the diaphragm aperture, and for operating the diaphragm of the lens at the front end of the intermediate tube from the camera located at the rear end of the tube, with provision for adjusting these mechanisms properly when the camera is turned to change the format, without turning the objective at the front of the tube. It is not necessary to detach either the camera or the lens when changing from one focusing mechanism to the other, or when turning the camera to change the format.

Focusing system for long focal length objectives

An adjustment device for a macrolens objective wherein a first lens group and a second lens group are axially displaceable is constructed so that the rotary movement necessary to move the second lens group in an axial direction is derived from the axial movement of the first lens group. There is no direct connection between the first lens holder and a stationary housing. The first lens group holder is threadably attached to the focusing ring which in turn is threadably attached to the lens housing by threads of equal but opposite pitch. The axial movement of the first lens holder is transmitted to the second lens holder, preferably, by an intermediate ring having internally threaded helical grooves. The first lens holder is engaged in the helical grooves of the intermediate ring, which ring in turn is engaged in internally threaded helical grooves of the same pitch of a cylindrical portion of the second lens holder. The rotary movement of the cylindrical portion causes the second lens holder to move axially relative to the lens housing to which it is threadably engaged.

Adjustable mechanism for a photo objective

A diaphragm for photographic cameras and the like, of the type where the diaphragm closes down rapidly from a wide open aperture for viewing to a preselected smaller aperture for picture taking, immediately prior to the actual exposure. The usual slotted ring connected to the diaphragm leaves or blades is stopped in its running down movement by contact with an interception ring whose position is determined by a diaphragm presetting member, the contact between the interception ring and the presetting member including a resiliently displaceable ball. As the slotted ring runs down, it is stopped by impact with the interception ring, which absorbs some of the kinetic energy of the slotted ring, and the resiliently mounted ball connection with the position determining lever (stationary at this time) allows the interception ring to move slightly further beyond the position to which it has been preset, thus bringing the moving parts to a smooth cushioned stop and effectively damping any rebound or bounce which might otherwise occur as a result of quickly stopping the fast running down movement of the diaphragm.

Growing community of inventors

Aalen, Germany

Dieter Rossmann