Patent ID: 7920783

Claim:
A camera assembly which comprises a camera housing and a plurality of interchangeable lenses, any one of which can be attached to the camera housing for capturing an image; each lens having a body and a lens system comprising at least one lens element that is movable relative to the lens body to alter the focus distance of the lens, the lens having a focal length that differs from the focal length of the or each other lens; wherein each lens has a focus scale on one of the lens system and the lens body that comprises a plurality of focus distance marks, and a focus index mark on the other of the lens system and the lens body, so that the lens can be focused at a desired focus distance by relative movement of the focus scale and the focus index mark to align the focus index mark with the focus distance mark on the focus scale corresponding to the desired focus distance; the focus scale extending between a position corresponding to a far focus distance and a position corresponding to a close focus distance, and being divided into at least two sub-ranges that adjoin at a position corresponding to an intermediate focus distance, the sub-ranges having different curves defining their focus distance marks on the focus scale for the at least one lens element that is movable relative to the lens body and for at least one of the interchangeable lenses, one of the sub-ranges being a principal sub-range wherein the relative position of the focus scale and the focus index mark that is required to focus the lens at any focus distance within the principal sub-range is substantially the same for at least two lenses.