Abstract: Disclosed is a photographic objective with a long focal length and a fastening device for a stand comprises a tubular structural element carrying optical elements, surrounded by an essentially annular holder. This holder is stationary in the axial direction and rotatable around the structural part. In addition to the fastening element capable of being joined to the stand, there is mounted in the outer wall of the holder means for locking the holder in predetermined positions.

Abstract: A photographic camera arrangement is disclosed for cameras which are intended to accept only certain interchangeable lens assemblies. For identification purposes, the bayonet segments of the camera housing and the bayonet segments of the lens assembly, respectively, are furnished with depressions, notches or like recesses and with stubs, ridges or like protrusions which will permit attachment of certain lens assemblies to only a given camera or series of cameras.

Abstract: In an interchangeable lens assembly for single lens reflex cameras the f-stop preselection ring is provided with a first transmission element for transmitting the preselected f-stop value into the light metering instrument of the camera housing, and with a second transmission element for controlling a device in the camera housing which indicates the preselected f-stop value. Said first and second transmission elements are parts of one common setting member which is in such a manner fixedly mounted on the preselection ring that -- when the preselection ring is in its base position -- said first transmission element assumes the same position in all interchangeable lenses while said second transmission element assumes positions that vary according to the maximum opening of the lens.

Abstract: Photographic camera with through the lens exposure metering where the exposure meter is equipped with a silicon- or gallium-arsenide-phosphorus-diode mounted in the space behind the objective and receiving the light. The exposure meter is switchable between integrating and selective metering mode. Two optical systems (12,13) are mounted in front of the light-sensitive diode (10) and are located in the illumination beam being measured. Either of the optical systems is selectively brought into position into the beam in front of the diode (10). One of the systems, namely (13), guides the light from almost the entire object space onto the diode (10). The other system (12) guides only light from a restricted sector of the object space onto the diode (10).

Abstract: A single lens mirror reflex camera with spring biased diaphragm and with exposure metering and controlling system having a central operation mode selection switch for switching between several operation modes, is improved by providing indicators at the camera which are switched in when the "automatic aperture" operation mode is selected and are recognized as warning displays by the user, and by providing switching means at the stop preselection ring of the objective and at the camera, which turn off the indicators in the camera proper when the smallest aperture is set at the stop preselection ring.