Patent ID: 7753603
Filing Date: 2010-07-13
Classification: G03B

Abstract:
1. A digital camera system comprising: a first camera body including a first image sensor and having a first flange focal length; a first optical device constituted of a plurality of optical elements arranged in a photographing optical path of the first image sensor; a first lens adapted to the first camera body, which is designed to have the minimum generation of the optical aberration in combination with the first optical device; a second camera body including a second image sensor and having a second flange focal length which is shorter than the first flange focal length; a second optical device constituted of a plurality of optical elements arranged in a photographing optical path of the second image sensor; a second lens adapted to the second camera body, which is designed to have the minimum generation of the optical aberration in combination with the second optical device; and an intermediate adapter having a lens detachable portion for detachably attaching the first lens on one end of the intermediate adapter and having a lens detachable portion for detachably attaching the second camera body on the other end thereof, wherein the intermediate adapter includes a third optical device which does not have any optical power to minimize the optical aberration in the combination of the first lens with the second optical device; a first optical equivalent amount Σ{ti×(1−ni)/ni} of the first optical element is larger than a second optical equivalent amount Σ{tj×(1−nj)/nj } of the second optical equivalent amount, in which i and j each is an integer of 1, 2, . . . given to each optical element of the first and second optical devices from a lens side, ni is a refractive index of each optical element of the first optical device, ti is a thickness thereof, nj is a refractive index of each optical element of the second optical device, and tj is a thickness thereof; and a sum Σ{tk×(1−nk)/nk}+Σ{tj×(1−nj)/nj } of a third optical equivalent amount Σ{tk×(1−nk)/nk} and the second optical equivalent amount Σ{tj×(1−nj)/nj } is substantially equal to the first optical equivalent amount Σ{ti×(1−ni)/ni }, in which k is an integer of 1, 2, . . . given to each optical element of the third optical device from a lens side, nk is a refractive index of each optical element of the third optical device, and tk is a thickness thereof.