Abstract: The invention relates to an expensive zoom lens that has a zoom ratio of as high as about 5 and high optical performance and is very thin in its depth direction. With the invention, the optical path of the optical system is easily bendable by means of a reflecting optical member. The zoom lens includes a first lens group G1 having positive power, a second lens group G2 having negative power, a third lens group G3 having positive power and a fourth lens group G4 having positive power, and comprises five lens groups in all. The first lens group G1 comprises, in order from its object side, a lens component of negative refracting power, an optical path-bending reflecting optical member P and a lens component of positive refracting power.

Abstract: A three-group zoom lens, includes, in order from an object side thereof: a first lens group having a negative refractive power, including in order from the object side: a negative-power first lens; and a positive-power second lens, wherein the first lens group including at least one aspherical surface, a second lens group having a positive refractive power, including in order from the object side thereof, a positive-power first lens; a positive-power second lens; and a negative-power third lens; wherein the positive-power second lens and the negative-power third lens are cemented together to form a meniscus-shaped cemented lens that faces a convex surface to the object side and the second lens group has aspherical surfaces on at least two surfaces other than a cemented surface of the cemented lens; and a third lens group having a positive refractive power, including: a positive-power single lens having only a spherical surface.

Abstract: The invention relates to a small-format yet high-performance two units or three units type zoom lens with a negative unit at the front, which has a zoom ratio of about 3, an angle of view of as wide as 60° at the wide-angle end and high image-formation capability, and is much less susceptible to chromatic blurring, with a compact lens barrel. The zoom lens comprises a first lens unit G1 of negative refracting power and a second lens unit G2 of positive power, wherein zooming is implemented by varying the space between the lens units. The first lens unit G1 is made up of one negative lens L11 and one positive lens L12, two in all, and satisfies specific conditions with respect to their refractive index and Abbe constant.

Abstract: The invention relates to an expensive zoom lens that has a zoom ratio of as high as about 5 and high optical performance and is very thin in its depth direction. With the invention, the optical path of the optical system is easily bendable by means of reflecting optical members. The zoom lens comprises a plurality of lens groups G1 to G5, and has a lens group F (G1) located nearest to the object side thereof. The first optical path bending is carried out by the first reflecting optical member PR located in the lens group F, and the second optical path bending is carried out by the second reflecting optical member RM located on an image side of the zoom lens with respect to the lens group F in a direction different from the first optical path bending direction. The lens group F remains substantially fixed with respect to an image plane I during zooming.

Abstract: The invention relates to an expensive zoom lens that has a zoom ratio of as high as about 5 and high optical performance and is very thin in its depth direction. With the invention, the optical path of the optical system is easily bendable by means of a reflecting optical member. The zoom lens includes a first lens group G1 having positive power, a second lens group G2 having negative power, a third lens group G3 having positive power and a fourth lens group G4 having positive power, and comprises five lens groups in all. The first lens group G1 comprises, in order from its object side, a lens component of negative refracting power, an optical path-bending reflecting optical member P and a lens component of positive refracting power.

Abstract: A three-group zoom lens, includes, in order from an object side thereof: a first lens group having a negative refractive power, including in order from the object side: a negative-power first lens; and a positive-power second lens, wherein the first lens group including at least one aspherical surface, a second lens group having a positive refractive power, including in order from the object side thereof, a positive-power first lens; a positive-power second lens; and a negative-power third lens; wherein the positive-power second lens and the negative-power third lens are cemented together to form a meniscus-shaped cemented lens that faces a convex surface to the object side and the second lens group has aspherical surfaces on at least two surfaces other than a cemented surface of the cemented lens; and a third lens group having a positive refractive power, including: a positive-power single lens having only a spherical surface.

Abstract: A camera includes a screen on which an image of an object is projected, a plurality of reflection surfaces for erecting the image on the screen, and an eyepiece system with positive refracting power for observing the image. In this case, the eyepiece system includes, in order from the object side, a first lens component with positive refracting power, a second lens component with positive refracting power, and a third lens component with negative refracting power. Spacings between the first lens component and the second lens component and between the second lens component and the third lens component are changed to thereby make a diopter adjustment, and the camera satisfies the following conditions: 0.15<tan(S)<0.35 2.00<fb/Y<4.00 ?0.80<f3/f<?0.

Abstract: A camera includes a screen on which an image of an object is projected, a plurality of reflection surfaces for erecting the image on the screen, and an eyepiece system with positive refracting power for observing the image. In this case, the eyepiece system includes, in order from the object side, a first lens component with positive refracting power, a second lens component with positive refracting power, and a third lens component with negative refracting power. Spacings between the first lens component and the second lens component and between the second lens component and the third lens component are changed to thereby make a diopter adjustment, and the camera satisfies the following conditions: 0.15<tan(S)<0.35 2.00<fb/Y<4.00 −0.80<f3/f<−0.

Abstract: A camera includes a screen on which an image of an object is projected, a plurality of reflection surfaces for erecting the image on the screen, and an eyepiece system with positive refracting power for observing the image. In this case, the eyepiece system includes, in order from the object side, a first lens component with positive refracting power, a second lens component with positive refracting power, and a third lens component with negative refracting power.

Abstract: The invention relates to a four- or five-group zoom lens that ensures wide-angle performance, high zoom ratios and high quality with a more reduced number of lenses than ever before. The zoom lens comprises, in order from its object side, a first lens group G1 having positive power, a second lens group G2 having negative power, a third lens group G3 having positive power, a fourth lens group G4 having negative power and a fifth lens group G5 having positive power. The fourth lens group G4 comprises one lens. For zooming, all the spacings between the respective lens groups vary and the first lens group G1 moves in such a way as to arrive at the object side at the telephoto end position rather than at the wide-angle end position.

Abstract: An image pickup apparatus comprising a first lens unit which comprises at least a negative lens element and at least a positive lens element and has negative refractive power, a second lens unit which has positive refractive power, and an optical path bending reflecting optical element which has a variable reflecting surface disposed in an airspace between a most object side lens component of the first lens unit and a most object side lens component of the second lens unit. This image pickup apparatus changes a magnification by moving the second lens unit along an optical axis and corrects a deviation of an image location by varying a shape of the variable reflecting surface of the reflecting optical element.