Archived posting to the Leica Users Group, 1998/02/01
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]From Rudolf Kingslake, A HISTORY OF THE PHOTOGRAPHIC LENS, pp. 141-142: "It (the reversed-telephoto or retrofocus design) has several advantages over a normal lens of the same focal length and aperture: (a) Obtaining a short overall focal length with elements of a larger and more manageable size, (b) Increasing the back focal distance beyond its usual magnitude, and (c) Designing a system that is favorable for both a high relative aperture and a wide-angular (sic) field. In light of the third advantage, we may well ask why the reversed telephoto type is not used for all applications. The reasons are that such a lens is physically large (advantage (a)), and it must be of complex construction to correct all the aberrations, making it an expensive item." Marc msmall@roanoke.infi.net FAX: +540/343-7315 Cha robh bas fir gun ghras fir!