Pentax lens data manuals normally specify the angle of view of a lens as a diagonal measure, which is difficult to relate to. This table presents the horizontal angle of view for SLR lenses when used on a 35mm film camera and when used on a digital SLR with a 1.5 crop factor like the Pentax *ist D, DS, DL, K100D, or K10D.
The following graph is a handy tool when deciding which lenses to buy. Click it to view it in full-size. It is a large image, so if you have a small screen, be sure to maximize your window or the image may apper distorted. (Internet Explorer: Press F11)