Abstract: A small, high performance zoom optical system has a simple structure that includes a positive lens group having a positive refractive power and a negative lens group having a negative refractive power arranged on an image side of the positive lens group. The positive lens group includes, in order from an object side, a first lens component with a negative refractive power, a second lens component with a negative refractive power and a third lens component with a positive refractive power. The first lens component has a meniscus shape with a concave surface facing the object side. Zooming is performed by changing the distance between the positive lens group and the negative lens group.

Abstract: A zoom lens system in which the back focus variations that accompany the movement of a shift lens unit can be compensated. During image shifting, the shift lens unit can be moved in a direction substantially perpendicular to an optical axis in order to shift an image. The shift lens unit also moves a small amount along the optical axis, thereby creating a back focus variation. A focusing lens unit is provided that moves along the optical axis to compensate for the variations in the back focus created by the shift lens unit during image shifting. A variation amount of the spherical aberration for the highest marginal rays at each focal length condition, when the shift lens unit undergoes a small change in position along the optical axis, divided by the amount of movement of the shift lens unit in the perpendicular direction is less than zero and greater than negative one.

Abstract: A compact zoom lens system that moves during zooming from a maximum wide-angle state to a maximum telephoto state also can shift an image to compensate for vibrations (shaking). The zoom lens system comprises first through fifth lens groups. During zooming at least the first lens group and the fifth lens group move toward the object side so that a distance between the first lens group and the second lens group increases; a distance between the second lens group and the third lens group decreases; a distance between the third lens group and the fourth lens group increases; and a distance between the fourth lens group and the fifth lens group decreases. At least one of the lens elements that comprise the fourth lens group is a shift lens group that shifts the image by moving in a direction substantially perpendicular to the optical axis. The zoom lens system also satisfies several conditions.

Abstract: An illuminating optical system including a light emitting device for supplying illuminating light, a directing member for directing the light beam from the light emitting device by refracting action, and a moving device for moving at least one of the light emitting device and the directing member in a direction differing from the direction of the optical axis of the directing member and varying the spacing between the light emitting device and the directing member to thereby vary the illumination range at a predetermined distance.

Abstract: A variable focal length optical system includes, in the following order from an object side, a first lens unit having a negative refractive power and a second lens unit having a positive refractive power, wherein the focal length of an entire lens system changes when a distance between the first lens unit and the second lens unit is changed, and the following condition is satisfied:0.3<f2/.vertline.f1.vertline.<0.5where f1 is the focal length of the first lens unit, and f2 is the focal length of the second lens unit.

Abstract: A camera having an apparatus for correcting parallax includes viewfinder optical system for viewing an object. A shooting lens system for photographing the object is disposed such that the optical axis of the shooting lens system is different from the optical axis of the viewfinder optical system. The shooting lens system includes a correcting lens group such that image shift is accomplished by decentering the correcting lens group. A focusing lens group, spaced from the correcting lens group, is moveable along the optical axis of the shooting lens system. Parallax that is created by changes in the position of the object is corrected by accomplishing an image shift by the shooting lens system.

Abstract: To provide a zoom lens in which focussing is possible with a small displacement and which is capable of close range focussing with superior imaging performance. The present invention provides a zoom lens capable of focussing at close range, of the type equipped with at least two lens units having negative refractive powers and arranged so as to be adjacent to each other, wherein focussing on close range objects is accomplished by causing one of the at least two lens units to move along the optical axis; and, the conditions:(.beta.a-.beta.a.sup.-1).sup.-2 <0.8.beta.a/.beta.b>0are satisfied, where .beta.a is the lateral magnification of the close range focussing lens unit at the maximum telephoto state in an infinite focus state, and .beta.b is the lateral magnification of the close range focussing lens unit at the maximum wide-angle state in an infinite focus state.

Abstract: In a variable focal length optical system which has, in succession from an object side, a first lens unit G1 having a positive refractive power, a second lens unit G2 having a negative refractive power, a third lens unit G3 having a positive refractive power, a fourth lens unit G4 having a positive refractive power, and a fifth lens unit G5 having a negative refractive power, when the focal length is varied from the maximum wide-angle state to the maximum telephoto state, at least the fifth lens unit G5 moves toward the object side, so that a first variable air gap between the first lens unit G1 and the second lens unit G2 increases, a second variable air gap between the second lens unit G2 and the third lens unit G3 decreases, a third variable air gap between the third lens unit G3 and the fourth lens unit G4 increases, and a fourth variable air gap between the fourth lens unit G4 and the fifth lens unit G5 decreases, the second lens unit G2 at least has a negative sub lens unit G21 which is disposed at a po

Abstract: The zoom lens of present invention includes, in order from the object side, a first lens group of negative refractive power and a second lens group of positive refractive power, such that each lens group moves during zooming from the maximum wide-angle state to the maximum telephoto state so that the distance between the first lens group and the second lens group decreases. The second lens group has, in order from the object side, a first lens subgroup of positive refractive power, having first and second lens units of positive refractive power, and a second lens subgroup of negative refractive power. The zoom lens satisfies at least one of the following conditions:0.2<Bfw/fw<0.750.6<.vertline.f1/(fw.times.ft).sup.1/2 <0.950.4<f2a/.vertline.f2b.vertline.<0.

Abstract: An optical system includes, in the following order from the object side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a negative refractive power, a fourth lens unit having a positive refractive power, a fifth lens unit having a positive refractive power, and a sixth lens unit having a negative refractive power. At least the first and sixth lens units move toward the object side upon changing the focal length from the maximum wide-angle state to the maximum telephoto state in such a way that the gap between the first and second lens units increases, the gap between the third and fourth lens units decreases, and the gap between the fifth and sixth lens units decreases.

Abstract: A zoom lens is capable of focusing at a close range and the focusing lens group can be controlled with a small memory capacity. The zoom lens includes, in order from the object side to the image side of the zoom lens, a first variable power unit GH, which has at least two variable power zoom lens groups movable along the optical axis for zooming, and a focusing lens group GF movable along the optical axis when focusing on close range objects. The magnification BF of the focusing lens group GF is selected such that 1/.vertline..beta.F.vertline.<0.35 is satisfied over the entire zooming range of the zoom lens from wide-angle end to telephoto end.

Abstract: A focal point position correction apparatus for a camera with a zoom lens system, has an adjustment amount calculation device for calculating an adjustment amount .delta.h of at least one lens unit Gh in the zoom lens system using a formula based on focal length information that defines a change amount corresponding to the focal length of the entire lens system and correction coefficients pre-stored for back focus adjustment, and a lens unit driver for moving the lens unit Gh by the adjustment amount .delta.h along the optical axis in the respective focal length states so as to correct any deviation, of the focal point position with respect to the film surface of a best image surface, caused by manufacturing errors, over the entire zooming range.

Abstract: A small zoom lens makes possible short distance focusing with a high zoom ratio and high performance using a simple lens barrel. A focusing second lens unit moves along the optical axis during focusing to the short distance object; a first lens unit is adjacent to and on the object side of the focusing lens unit; and a third lens unit is adjacent to and on the image side of the focusing lens unit. The second unit lens and the third lens unit move integrally together during zooming between a maximum wide-angle state and a maximum telephoto state. The focusing lens unit moves in conjunction with and relative to the second and third lens units. The first or the third lens unit has a positive focal length and the other has a negative focal length. Additionally, the first and third lens units satisfies the following condition:-0.6<(fa +fb)/(fa-fb)<0.4wherefa=focal length of the first lens unit, andfb=focal length of the third lens unit.

Abstract: In a variable focal length optical system wherein a shift lens unit constituting a portion of the optical system can be moved in a direction substantially perpendicular to the optical axis of the optical system to thereby shift an image, the shift lens unit is driven on the basis of the focal length information of the optical system to correct any variation in image position due to the vibration of the optical system. When, for example, a focusing lens unit movable along the optical axis during focusing on a short distance object is disposed more adjacent to the object side than the shift lens unit, the required amount of drive of the shift lens unit is calculated on the basis of the focal length information and a memorized predetermined coefficient.

Abstract: A wide-angle objective lens is comprised, from the object side, of a first lens component which is a negative meniscus lens having its convex surface facing the object side, a second lens component which is a meniscus lens having its convex surface facing the object side and having positive refractive power, a third lens component which is a cemented meniscus lens comprising a positive lens and a negative lens cemented together and having its convex surface facing the object side and having positive refractive power, a fourth lens component which is a positive meniscus lens having its concave surface facing the object side, and a fifth lens component which is a negative meniscus lens having its concave surface facing the object side. The wide-angle objective lens has a stop disposed between the second lens component and third lens component, and satisfies predetermined conditions.

Abstract: Disclosed is a zoom lens comprising at least three movable lens units. The zoom lens comprises a first lens unit disposed closest to an object side and having positive refractive force. The first lens unit includes a positive cemented lens constituted by a positive lens element and a negative lens element, with a concave side of the cemented surface facing the object side. The zoom lens also comprises a last lens unit disposed closest to an image side. Upon zooming from a wide angle end to a telephoto end, at least the first lens unit and the last lens unit move toward the object side so as to increase an air gap between the first lens unit and a lens unit adjacent to the first lens unit on the image side but to decrease an air gap between the last lens unit and a lens unit adjacent to the last lens unit on the object side. The zoom lens satisfies the following condition:0.7<f1/(fw.multidot.ft).sup.1/2 <1.

Abstract: Disclosed is a zoom lens comprising at least three movable lens units. The zoom lens comprises a first lens unit disposed closest to an object side and having positive refractive force. The first lens unit includes a positive cemented lens constituted by a positive lens element and a negative lens element, with a concave side of the cemented surface facing the object side. The zoom lens also comprises a last lens unit disposed closest to an image side. Upon zooming from a wide angle end to a telephoto end, at least the first lens unit and the last lens unit move toward the object side so as to increase an air gap between the first lens unit and a lens unit adjacent to the first lens unit on the image side but to decrease an air gap between the last lens unit and a lens unit adjacent to the last lens unit on the object side. The zoom lens satisfies the following condition:0.7<f1/(fw.multidot.ft).sup.1/2 <1.

Abstract: A variable focal length optical system includes, in order from an object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, a fourth lens group having a positive refractive power, and a fifth lens group having a negative refractive power. When the lens groups are moved from a wide-angle end to a telephoto end, at least the first lens group and the fifth lens group are moved toward the object side. In this case, the air gap along an optical axis between the first lens group and the second lens group, and the air gap along an optical axis between the third lens group and the fourth lens group are increased, respectively. At the same time, the air gap along an optical axis between the fourth lens group and the fifth lens group is decreased. In the variable focal length optical system, at least one lens group among the second to fourth lens groups carries out a focusing operation.

Abstract: A lens system has a front unit having a positive refractive power and a rear unit having a negative refractive power, in order from the object side, and performs a refractive power varying (zooming) operation by changing an air gap between the two units. The front unit is composed of three lens components of negative, negative, and positive refractive powers.

Abstract: In a zoom lens composed of at least a first lens unit G1, a second lens unit G2 and a third lens unit G3 in that order from an object side, a variable magnification-focusing lens unit GF disposed nearer to an image side than the first lens unit is shifted along an optical axis to perform a refractive power varying operation from a wide-angle end to a telephoto end and a focusing operation to a near distance object, and an air gap along the optical axis between the variable magnification-focusing lens unit GF and a lens unit GE adjacent to the variable magnification-focusing lens unit GF is approximately constant at a predetermined photographing distance without depending on variation in effective focal length of the entire lens system.