Abstract: Improvements in an optical system for a compact camera having an improved form of a zoom objective lens arranged substantially enclosed within the housing of the camera which is made compact by a twice folded optical path and a through-the-lens viewing system.

Abstract: A light mixing system for use in a photographic enlarger in which light from a light source is admitted to a light mixing module through an aperture (and/or through a light modifying filter system for color correction for color enlargements) to mix light beams to provide substantially uniform energy distribution at the outlet port of the light mixing module. The light mixing module includes a lens having a conical surface to receive the admitted light beams and to direct the light beams along angular paths with respect to the axis of the conical surface. The lens interfaces with a diffuser means comprising a multitude of fiber optic elements each adapted to receive light beams along the angular path, to transmit and reflect the light beams and to cause the light beams to depart the exit end of the fiber optic element in the form of a fan or cone of substantially the same angle as that of the light beams at the lens for mixing said beams.

Abstract: There is disclosed herein an electronic system and circuits for photographic devices for performing certain photographic calculation and control functions. In an exemplary embodiment, the system is particularly useful for performing metering, calculation and control of shutter timing and/or diaphragm aperture opening for a camera. The system includes a logarithmic converter for converting an electrical signal proportional to light intensity passing through the camera lens from a linear value to a log value, and a calculator responsive thereto and to other input parameters, such as film sensitivity, open aperture, selected aperture and selected shutter speed which, in turn, calculates an appropriate shutter speed and an appropriate aperture. The output of the calculator is connected to a circuit, which includes the log converter in a feedback loop for performing an antilog function and for controlling shutter speed and/or diaphragm aperture.

Abstract: Disclosed is a very compact, medium wide angle lens of the inverted telephoto type, capable of covering total field angles of up to 63.degree.; comprising six elements including a singlet front group of strong negative power and having extremely good aberrational correction.

Abstract: There is disclosed herein an electronic system and display system for a camera. The electronic system receives various inputs pertaining to film speed, brightness, selected shutter speed and a relative aperture value, and provides outputs for control of shutter speed and aperture as well as display of these parameters. An electrical signal representing a relative aperture value is provided for the display system, and a mechanical input is provided to the display system representing a fixed aperture value, such as minimum aperture value or A.sub.o. The electrical and mechanical inputs are combined to provide a display of an absolute aperture value, such as computed aperture value A.sub.c. Details of the camera electronic system also are disclosed.

Abstract: A zoom lens having a wide field angle and two movable groupings to vary the equivalent focal length, the front grouping comprising a front positive group, a negative group comprising a plurality of negative elements, and a rear positive group. In zooming the rear grouping moves forward to increase the equivalent focal length while the front grouping moves backward to maintain the image plane. The front grouping is independently movable for focusing.

Abstract: A zoom lens having a semi-field angle of between 12.6.degree. and 6.3.degree. capable of focusing at a 1:2 image-to-object distance ratio while providing a comfortable working range. The lens comprises a movable focusing group, a second stationary compensating group, two zooming groups which move axially relative to the lens and differentially of each other, and a fifth rear master group.

Abstract: A mechanism for a zoom lens of the type in which the aperture defining diaphragm mechanism moves axially of the lens and changes the position of the exit pupil, where the mechanism modifies the aperture with changing focal length to maintain constant relative aperture at full relative aperture and further predetermines the stop down of the diaphragm mechanism as a function of selected relative aperture and focal length.

Abstract: Apparatus for mixing light wherein the various color components are efficiently mixed to a uniform distribution. Light is introduced into one end of an optically clear rod-like member through a diffuser and is mixed therein through internal reflection.

Abstract: Circuits and auxiliary elements for use with a device for controlling the emission of light pulses from a flash unit, which light pulses are produced by the discharge of current pulses from a capacitor, the device including a light sensing element for receiving light produced by the flash unit and reflected from an object in the light path. One such circuit includes a switch which is selectively operable to permit control of termination of the emission of light pulses at either one of two light intensity output levels. Another circuit permits one light sensing element to normally trigger the emission of a light pulse in response to a light pulse from a remote unit, and to be selectively connected to subsequently control termination of such emission. One such element is a special gas filled switching tube having two internal electrodes for triggering conduction through the tube in response to a low voltage.

Abstract: A light mixing device of optically clear light transmitting material where the various color components of light introduced in the input end of the device are efficiently mixed by internal reflection through the length of the mixer. The mixer may be either linear or curved and includes axially extending reflective surfaces internal of its outer periphery.

Abstract: An optica image forming screen which comprises a multiplicity of light-transmitting elements in a matrix of light-absorbing elements so that light incident upon the elements at an angle greater than a predetermined angle will be internally absorbed by the elements, with no significant reflection internal to the elements and with element size conducive to a scattering effect by using diffraction in the image space.

Abstract: A wide angle lens system of the retrofocus type having a ratio of back focal length to equivalent focal length of greater than two and a large relative aperture. The lens system comprises 13 elements in nine groups including four consecutive doublets and is capable of focusing to an object distance of eleven equivalent focal lengths from the front vertex thereof.

Abstract: A camera of the so-called pocket type having an objective lens including means for varying the equivalent focal length. The optical axis of the overall lens is folded to have two forward portions and a connecting lateral portion with the primary zooming elements on the lateral portion. The view finder system axis is a linear continuation of the lateral objective axis.

Abstract: This disclosure relates to a Wide Angle Lens of the retrofocus type having a new lens group arrangement which comprises from the object end to the image end a first negative group, a second negative group in the form of a meniscus having a concave image side surface, a third positive group having a convex object side surface, a fourth positive group having a convex image side surface, a fifth negative group, and a sixth positive group having convex image and object side surfaces.

Abstract: This disclosure relates to variable focal lens having zooming and compensating groups movable axially in a non-linear relation. A single operating member is rotatable to move the front focusing group without moving the other groups, and movable axially to shift the zooming and compensating groups without moving the focusing group. Axial movement is imparted to the mount for the zooming group, and relative movement of the compensating group is controlled by rotative movement of the zooming group.

Abstract: A lens of five elements comprising a first bi-convex element, a second meniscus element, a third bi-concave element, a fourth meniscus element, and a fifth bi-convex element with an aperture stop between the meniscuses and the concave surfaces of the meniscuses facing the aperture.

Abstract: Apparatus for converting a camera metering system from a manually set electronic metering system into an automatic, aperture-preferred metering system uses sensing means responsive to exposure signals provided by the metering system of the camera for providing a signal to drive means for automatically selecting the proper shutter speed.

Abstract: There is disclosed herein a voltage regulator for a power supply for load devices such as electronic photoflash units. The voltage regulator supplies power to charge the main capacitor of the photoflash unit to an appropriate voltage, and uses a semiconductor series regulator circuit. The voltage regulator provides medium-to-long term heat integration to terminate power supplied to the electronic flash unit in the event of a thermal overload in order to protect the electronic flash unit. The circuit includes a ready indicator to indicate when the main capacitor of the flash unit has reached the appropriate charge, and also includes an overload indicator to indicate an overload condition.