Archived posting to the Leica Users Group, 1997/07/22
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]There seems to be again a number of messages dealing with lens comparisons between lens with the same focal length but different maximum apertures and even comparisons between different focal lengths and different maximum apertures. It seems useful to restate a few important general observations. 1. In comparing lenses of the same focal length and different maximum apertures, it is extremely rare for a small f-number maximum aperture lens to have better optical properties as it is stopped down than a lens of smaller maximum aperture. Thus, the f:1.4 or F:2 lens is only worth the expense (and weight, bulk, etc.) when one needs the larger aperture for light-gathering or smaller depth-of field reasons. Also the larger aperture lens usually have more elements and hence more flare no matter how good the coating or freedom from inclusions or other optical inhomogeneities might be. 2. Comparisons of resolution, contrast, etc. across different focal lengths is not very useful as flare and other optical properties vary enormously, particularly as one goes to the shortest focal lengths (35mm,24mm). 3. In my experience, there are no bad Leica lens; they just have different features and are manufactured for different purposes. It seems wiser to think about what you want to photograph and then obtain the equipment necessary to do it most efficiently. The photograph is in the brain, not the lens or the camera. Alan Bearden