摘要:
A compound zoom lens optical system includes a variable focal length photographing lens consisting of a first lens group having a positive refracting power, and a second lens group having a negative refracting power from an object side in turn. A conversion lens is separably added to an image side of the variable focal length photographing lens. The conversion lens is simultaneously movable along an optical axis to be interlocked with at least one of the first and second lens groups of the variable focal length photographing lens so as to change a synthesized focal length with said variable focal length photographing lens. The variable focal length photographing lens and the conversion lens satisfy the following conditions:-1.5
摘要:
A variable focal length photo-taking optical system includes a photo-taking objective lens, and a conversion lens removably added to the photo-taking objective lens and relatively movable along the optic axis with at least some lens groups of the photo-taking objective lens to change the combined focal length of the photo-taking objective lens and the conversion lens.
摘要:
In a phototaking lens with the focal length variable from a predetermined value at the wide-angle end position to another predetermined value at the telephoto end position, a part of lens elements constituting the phototaking lens is rendered movable relative to other lens components. There is provided means for converting the lens, by the relative movement of a part of the lens elements, to a panorama state with a focal length even shorter than that at the wide-angle end position. The phototaking lens is a zoom lens having a first lens group of a positive refractive power and a second lens group of a negative refractive power in the order from the object side, wherein the focal length is varied by a change in the distance between the first and second lens groups, and the panorama state is obtained by a relative movement of the first lens group relative to the second lens group.
摘要:
In a phototaking lens with the focal length variable from a predetermined value at the wide-angle end position to another predetermined value at the telephoto end position, a part of lens elements constituting the phototaking lens is rendered movable relative to other lens components. There is provided means for converting the lens, by the relative movement of a part of the lens elements, to a panorama state with a focal length even shorter than that at the wide-angle end position. The phototaking lens is a zoom lens having a first lens group of a positive refractive power and a second lens group of a negative refractive power in the order from the object side, wherein the focal length is varied by a change in the distance between the first and second lens groups, and the panorama state is obtained by a relative movement of the first lens group relative to the second lens group.
摘要:
In a finder optical system wherein a field frame and a field lens are placed near an objective lens and a real image plane made by the objective lens and a prism having a reflecting surface is disposed between the field frame and an eyepiece, a transmitting surface substantially perpendicular to the optical axis of reflected light reflected by the reflecting surface of the prism is provided on the reflecting surface of the prism or by cutting away the reflecting surface, and an information display system for displaying desired information through that transmitting surface is provided. The information display system is provided at a position optically symmetrical with the field frame.
摘要:
A rectangular prism includes an entrance surface for receiving light, an exit surface from which the light emerges, two reflecting surfaces orthogonal to each other for directing the light ray incident from the entrance surface to the exit surface, and a groove of V-shaped cross-section disposed in the boundary between the entrance surface and the exit surface.
摘要:
A Keplerian finder optical system composed of, in succession from the object side, an objective lens of a positive refractive power, a field lens of a positive refractive power positioned in the vicinity of the focal plane of the objective lens, and an eyepiece lens for observing an image of the object formed on the focal plane of the objective lens, comprises a field diaphragm positioned in the vicinity of the focal plane of the objective lens, a first reflecting device with two reflecting faces positioned in the optical path between the objective lens and the field diaphragm, and second reflecting device with two other reflecting faces, positioned between the field diaphragm and the eyepiece lens.
摘要:
A variable magnification zoom lens system comprising: in order from the object side, a first lens group having a negative refractive power and a focal length f1; a second lens group having a positive refractive power; and a third lens group having a positive refractive power and a focal length f3 with the first and second lens group arranged to be driven together such that when zooming is performed from the maximum wide-angle state to the maximum telephoto state of the zoom lens system, the first lens group and the second lens group move such that the distance between the first lens group and the second lens group is decreased, and at the same time, the distance between second lens group and the third lens group is increased and with the following condition being fulfilled: 0.4
摘要:
A position controlling device in a lens system with a variable focal length with high-precision focusing having a small amount of required recorded information, even when there are large number of divisions of the object distance and of the focal length includes a distance measuring device that detects the object position and transmits photographic distance information. A detecting device detects the movement amount from a standard position of the movable lens group of the lens system when the focal length of the lens system changes. A calculating device calculates the required movement of the focusing lens unit of the lens system, based on the photographic distance information and the movement amount of the movable lens unit. Finally, a controlling device drives the focusing lens unit and performs focusing, based on the required movement calculated by the calculating device. The movable lens unit moves monotonically to the object side or to an image side when the focal length of the lens system is changed. In this manner, the focusing movement required increases monotonically and gradually when the focal length of the lens system changes from the wide-angle end to the telephoto end for a given photographic distance.
摘要:
A camera comprises a photographing lens, a finder having its optical axis disposed substantially in parallel with the optical axis of the photographing lens and a lens drive for moving the photographing lens for focusing, the lens drive including a guide member for rectilinearly moving the photographing lens in a direction set at a predetermined angle to the optical axis of the photographing lens.