Ok, some more on the Curtis Color Stellar from the author of that website.

-> http://tech.groups.yahoo.com/group/h...phy/message/26

Curtis' solution to this problem was to design a retrofocus wide angle lens. This lens was named the Curtis Color Stellar. It has a focal length of 133mm (5.25 inches), but its back focal distance is approximately 210mm (8.25 inches). Thus the lens could be positioned 8.25 inches away from the focal plane, but it possesses the angle of view of a 133mm wide angle, which in this case is 60 degrees. Prior to introduction of the Color Stellar lens the standard lens on Curtis 4x5 cameras was 8.25 inches, with an angle of view of 38 degrees. It's obvious that 38 degrees is too tight for a variety of news images.