Archived posting to the Leica Users Group, 2001/02/26
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]On Mon, 26 February 2001, Rob McElroy wrote: > > > Good Luck and I may be in the minority, but I too find the test interesting. A question I have regarding the effect of the UV filter on lens > performance is: Do large diameter filters on fast lenses have more of an effect (even if it's negligible or small) than smaller filters on slower > lenses? The light rays passing through the center of a filter, pass through at a 90º angle to the filter's two surfaces. The light rays coming > through the edge of a large filter (like over a Noctilux) are coming through the filter's two surfaces at a more oblique angle. > Rob, Assuming a properly shaded system, the angle of incidence dosn't depend on the speed of the lens or the portion of the filter the light enters. A wide-angle lens will recieve light from a greater range of angles of incidence than a normal lens, and a long-focus or telephoto lens (again, properly shaded) will "see" light rays that are closer to parallel to the lens axis (i.e., perpendicular to the filter). Doug Herr Birdman of Sacramento http://www.wildlightphoto.com ___________________________________________________ The ALL NEW CS2000 from CompuServe Better! Faster! More Powerful! 250 FREE hours! Sign-on Now! http://www.compuserve.com/trycsrv/cs2000/webmail/