Zoom lens

A zoom lens comprising:

• a front lens group having a positive power, the front lens group consisting of a first lens having a negative power and a second lens having a positive power;
• and
• a rear lens group having a negative power, the rear lens group being movable relative to the front lens group along an optical axis for zooming;
• wherein the first lens has at least one aspherical surface, and is spaced from the second lens by a distance, wherein the zoom lens satisfies the following condition:
• 0<D2/Fw<0.1 (1)
• wherein D2 is the distance between the first and second lenses, and Fw is a total focal length of the zoom lens at a wide-angle end;
• wherein image side surfaces and object side surfaces of the first to third lenses are aspherical.

A zoom lens comprising:

• a front lens group having a positive power, the front lens group consisting of a first lens having a negative power and a second lens having a positive power;
• and
• a rear lens group having a negative power, the rear lens group being movable relative to the front lens group along an optical axis for zooming;
• wherein the first lens has at least one aspherical surface, and is spaced from the second lens by a distance, wherein the zoom lens satisfies the following condition:
• 0<D2/Fw<0.1 (1)
• wherein D2 is the distance between the first and second lenses, and Fw is a total focal length of the zoom lens at a wide-angle end;
• wherein image side surfaces and object side surfaces of the first and second lenses and an image side surface of the third lens are aspherical.

A zoom lens comprising:

• a front lens group having a positive power, the front lens group consisting of a first lens having a negative power and a second lens having a positive power;
• and
• a rear lens group having a negative power, the rear lens group being movable relative to the front lens group along an optical axis for zooming;
• wherein the first lens has at least one aspherical surface, and is spaced from the second lens by a distance, wherein the zoom lens satisfies the following condition:
• 0<D2/Fw<0.1 (1)
• wherein D2 is the distance between the first and second lenses, and Fw is a total focal length of the zoom lens at a wide-angle end;
• wherein image side surfaces and object side surfaces of the first and second lenses and an object side surface of the third lens are aspherical.

A zoom lens comprising:

• a front lens group having a positive power, the front lens group consisting of a first lens having a negative power and a second lens having a positive power;
• and
• a rear lens group having a negative power, the rear lens group being movable relative to the front lens group along an optical axis for zooming;
• wherein the first lens has at least one aspherical surface, and is spaced from the second lens by a distance, wherein the zoom lens satisfies the following condition:
• 0<D2/Fw<0.1 (1)
• wherein D2 is the distance between the first and second lenses, and Fw is a total focal length of the zoom lens at a wide-angle end;
• wherein object side surfaces of the first to third lenses are aspherical.

A zoom lens comprising:

• a front lens group having a positive power, the front lens group consisting of a first lens having a negative power and a second lens having a positive power;
• and
• a rear lens group having a negative power, the rear lens group being movable relative to the front lens group along an optical axis for zooming;
• wherein the first lens has at least one aspherical surface, and is spaced from the second lens by a distance, wherein the zoom lens satisfies the following condition:
• 0<D2/Fw<0.1 (1)
• wherein D2 is the distance between the first and second lenses, and Fw is a total focal length of the zoom lens at a wide-angle end;
• wherein the rear lens group consists of a third lens having a negative power;
• said zoom lens further satisfying the following condition:
• 0.5<.vertline.(C.sub.as -C)/(N-1)/.PHI..sub.G1 .vertline.<10(2)
• wherein C is a radius of curvature of a base surface of the aspherical surface, N is an index of refraction of a medium forming the first lens, .PHI..sub.G1 is a power of refraction of the first lens, and C.sub.as is a local radius of curvature at a height Y relative to an optical axis, wherein 0.7Y.sub.max <Y<1.0Y.sub.max, and Y.sub.max is a maximum effective aperture of the first lens.

A zoom lens comprising:

• a front lens group having a positive power, the front lens group consisting of a first lens having a negative power and a second lens having a positive power;
• and
• a rear lens group having a negative power, the rear lens group being movable relative to the front lens group along an optical axis for zooming;
• wherein the first lens has at least one aspherical surface, and is spaced from the second lens by a distance, wherein the zoom lens satisfies the following condition:
• 0<D2/Fw<0.1 (1)
• wherein D2 is the distance between the first and second lenses, and Fw is a total focal length of the zoom lens at a wide-angle end;
• wherein the rear lens group consists of a third lens having a negative power;
• said zoom lens further satisfying the following condition:
• 1.8<.vertline.(C.sub.as -C)/(N-1)/.PHI..sub.G1 .vertline.<10(2)
• wherein C is a radius of curvature of a base surface of the aspherical surface, N is an index of refraction of a medium forming the first lens, .PHI..sub.G1 is a power of refraction of the first lens, and C.sub.as is a local radius of curvature at a height Y relative to an optical axis, wherein 0.7Y.sub.max <Y<1.0Y.sub.max and Y.sub.max is a maximum effective aperture of the first lens.