Patent classifications
G02B15/173
Zoom lens and image pickup apparatus including the same
Provided is a zoom lens including, in order from an object side: a first lens unit not moving for zooming; a second lens unit moving during the zooming; at least one lens unit moving during the zooming; and a rear lens group. The first lens unit includes a first lens sub unit not moving for focusing, and a second lens sub unit moving during the focusing. The first lens sub unit includes a negative lens and a positive lens. A focal length of the first lens unit, a distance on an optical axis from a lens surface closest to an image side of the first lens sub unit to a rear principal point position of the first lens sub unit, and a focal length of the zoom lens at a telephoto end are appropriately set.
Photographing lens
The present invention is directed to a photographing lens containing, in order from an object side: a first lens having a positive refractive power and a convex surface facing the object side; a second lens having a negative refractive power; a third lens having a positive refractive power; and a fourth lens having a negative refractive power and at least one aspheric surface, the photographing lens satisfying the following conditional expressions:
where L.sub.T denotes the distance on the optical axis between the object side of the first lens and the image side of the fourth lens; f denotes the total focal length of the photographing lens; and f.sub.3 denotes the focal length of the third lens.
Variable magnification optical system, optical device, and production method for variable magnification optical system
Comprising, in order from an object side: a first lens group G1 having positive refractive power; a second lens group G2 having negative refractive power; a third lens group G3 having positive refractive power; and a fourth lens group G4 having positive refractive power; upon zooming from a wide-angle end state to a telephoto end state, the first lens group G1 being fixed in the position in the direction of the optical axis, at least the second lens group G2 and the third lens group G3 being moved in the direction of the optical axis such that a distance between the first lens group G1 and the second lens group G2 is increased and a distance between the second lens group G2 and the third lens group G3 is decreased; and a predetermined conditional expression being satisfied, thereby providing a variable magnification optical system which can suppress variations in aberrations upon zooming and having excellent optical performance from a wide angle end state to a telephoto end state, an optical apparatus, and a method for manufacturing a variable magnification optical system.
Variable magnification optical system, optical device, and production method for variable magnification optical system
Comprising, in order from an object side: a first lens group G1 having positive refractive power; a second lens group G2 having negative refractive power; a third lens group G3 having positive refractive power; and a fourth lens group G4 having positive refractive power; upon zooming from a wide-angle end state to a telephoto end state, the first lens group G1 being fixed in the position in the direction of the optical axis, at least the second lens group G2 and the third lens group G3 being moved in the direction of the optical axis such that a distance between the first lens group G1 and the second lens group G2 is increased and a distance between the second lens group G2 and the third lens group G3 is decreased; and a predetermined conditional expression being satisfied, thereby providing a variable magnification optical system which can suppress variations in aberrations upon zooming and having excellent optical performance from a wide angle end state to a telephoto end state, an optical apparatus, and a method for manufacturing a variable magnification optical system.
Zoom lens and image pickup apparatus using the same
The zoom lens has an aperture stop arranged between the second lens unit and the fourth lens unit. During zooming from the wide angle end to the telephoto end, the distances between the lens units vary in such a way that the distance between the first lens unit and the second lens unit is larger at the telephoto end than at the wide angle end, the distance between the second lens unit and the third lens unit is smaller at the telephoto end than at the wide angle end, and the distance between the fourth lens unit and the fifth lens unit is larger at the telephoto end than at the wide angle end. The zoom lens satisfies the following conditional expression (1):
3.5≦LTL.sub.w/IH.sub.t≦8.9 (1).
Zoom lens system
A zoom lens system includes a positive first lens group, a negative second lens group, a positive third lens group, a negative fourth lens group, and a positive fifth lens group having a plurality of lens elements. During zooming from the short to long focal length extremities, at least the first, third and fifth lens groups move in an optical axis direction. A surface closest to the image side of the zoom lens system is a concave surface facing the image side. The following condition (1) is satisfied:
0.52<(m345t/m345w)/(ft/fw)<0.70 (1),
wherein m345w and m345t designate, at the short and long focal length extremities, respectively, the combined lateral magnification of the third, fourth and fifth lens groups when focused on an object at infinity; and fw and ft designate the focal length of the zoom lens system at the short and long focal length extremities, respectively.
ZOOM LENS AND IMAGING APPARATUS
The zoom lens includes, in order from an object side, a positive first lens group G1, a negative second lens group G2, a positive third lens group G3, a diaphragm, and a fourth lens group G4. During zooming, only the second lens group G2 and the third lens group G3 move. The first lens group G1 includes, in order from the object side, a cemented lens that is formed by cementing a positive lens and a negative meniscus lens convex toward the object side, a positive lens, and a negative lens. A conditional expression (1): −0.8<f1a/f1b<0 is satisfied, where f1a is a composite focal length of the first to third lenses from the object side of the first lens group G1, and f1b is a focal length of the fourth lens.
ZOOM LENS AND IMAGE PICKUP APPARATUS INCLUDING THE SAME
Provided is a zoom lens, including, in order from an object side to an image 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 positive refractive power; a fourth lens unit having a positive refractive power; a fifth lens unit having a negative refractive power; and a rear lens group including one or more lens units, in which the third lens unit is configured to move toward the object side during zooming from a wide angle end to a telephoto end, in which an interval between adjacent lens units is changed during zooming, in which the fourth lens unit is moved in a direction having a vertical component to an optical axis during image stabilization, and in which focal lengths of the third and fourth lens units are appropriately set.
Zoom lens and imaging apparatus
A zoom lens consists of a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having positive refractive power, and a fifth lens group having positive refractive power in this order from an object side. The third lens group consists of a 3-1st lens group having positive refractive power and a 3-2nd lens group having negative refractive power in this order from the object side. A hand shake blur is corrected by moving the 3-2nd lens group in a direction perpendicular to optical axis. Magnification is changed by changing distances between the lens groups while the fifth lens group is fixed.
Zoom lens and imaging apparatus
A zoom lens consists of a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having positive refractive power, and a fifth lens group having positive refractive power in this order from an object side. The third lens group consists of a 3-1st lens group having positive refractive power and a 3-2nd lens group having negative refractive power in this order from the object side. A hand shake blur is corrected by moving the 3-2nd lens group in a direction perpendicular to optical axis. Magnification is changed by changing distances between the lens groups while the fifth lens group is fixed.