This figure is commonly given in millimeters (mm). For example, my 8-inch SCT has a focal length of 2,032 mm. Imagine it like ...

SIGMA will develop interchangeable lenses with unprecedented specifications and performance by designs that benefit from the short flange focal length ... With the SIGMA 45mm F2.8 DG DN ...

"The Distagon T* 45mm lens is the all-purpose wide-angle lens in the Contax 645 auto focus system. The focal length of 45mm on a Contax 645 is approximately equivalent to 28mm in the 35mm format.

"The 45mm focal length of the all-new PC-E Micro Nikkor 45mm f/2.8D ED lens is ideal for a natural looking perspective that can be controlled creatively by the photographer. Featuring ED glass to ...