Camera and Lens System

A lens which can be attached to a camera housing for capturing an image;

• the 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;
• wherein the lens has a focus scale comprising a plurality of focus distance marks extending around part of the circumference of one of the lens system and the lens body, and a focus index mark on the other of the lens system and the lens body, so that the lens system can be moved to focus the lens at a desired focus distance by relative rotation of the focus scale and the focus index mark to align the focus index mark with the focus distance mare on the lens 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, one of the sub-ranges being a principal sub-range in which the position of the lens element(s) varies in proportion to relative angular position of the focus scale and the focus index mark, and the other of the sub-ranges being an additional sub-range in which the position of the lens system is not proportional to the relative rotation of the focus scale and the focus index mark.

A method of forming a range of interchangeable camera lenses, which comprises forming a number of lenses, 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 having a focal length that differs from the focal length of the or each other lens;

• and
• forming 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 lens 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, one of the sub-ranges being a principal sub-range wherein the relative movement 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.