Archived posting to the Leica Users Group, 1999/09/27
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Dave Strang wrote: >>> Another thing that comes to mind is the focus screen may not be compatible with a 180mm lens which is also an 2 aperature. Maybe ther eis another screen I can try. The Canon F-1n FN-SK screen was optimized for 300mm lenses or longer and it showed. It could not be used for shorter lenses. So maybe the R matte screen is the problem? Opinions requested. <<< Dave, Usually when a screen should/could not be used for some lenses it's because fresnel rings are meant for a certain focal length range or microprisms are designed for a specific aperture range. I've used the matte screens (with grid) with a wide variety of lenses, length from 19 to 560, aperture from 2.0 to 6.8, with no focus errors of this sort. I'd guess your screen isn't seated properly in the camera. Doug Herr Sacramento http://ourworld.compuserve.com/homepages/telyt