Archived posting to the Leica Users Group, 1998/02/10
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]On Mon, 9 Feb 1998, Jim Brick wrote: > At 08:38 AM 2/10/98 -0500, you wrote: > >At 08:28 PM 08-02-98 -0800, you wrote: > >>Just curious... how many of you that are posting on this resolution thread, > >>have a UV permanently mounted on your lens? Could be oxymoronic you know... Curious thing happend to me once. I was testing a Canon EF 200f2.8L ( seeing which were the best F stops ). I thought I may as well see what effect using my B+W circular polarizer would have. Now the bizarre thing was, I got better resolution with the polarizer than without. Now I have a few possible explenations. - - The reduced shutter speed meant that the shutter going off ( yes I was using mirror lock up ) had more time to settle down and thereby causes less vibration. The tripod I was useing was OK, but I have never liked the head, not ridgid enough. The B1 fixed that. - - The polarizer somehow effected the light, which allowed the lens to work more effectively ( a bit like using say a dark red filter to reduce the spectrum on has too work with ). I think this is very unlikely due to the polarizer being a circular type, i.e. it depolarizes the light before it leaves the filter. - - Focusing error ( most likely ) Now my conclusion was, If one has a clean, good quality filter on your lens, your photographic technique will let you down long before your filter will. Of course this is assuming you are shading your filter adequately. Duncan ( who may repeat this test some day ). PS the biggest difference I noticed with this lens was the increase in constast compared with the zoom I owned previously.