Archived posting to the Leica Users Group, 1999/09/21
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]At 9:42 AM -0800 9/21/99, Guy Bennett wrote: >lugnutz, > >have been following the 24mm/filter thread with some interest, and have >been intrigued by the various strategies suggested for checking for >vignetting. i had similar questions (and posted them over the summer) when >i bought the elmarit m 24mm this past june. my issue was not so much >vignetting caused by a filter alone, but rather vignetting caused by a >using a filter and a lens hood, as the lens hood wouldn't slip on >completely and 'lock into place' if i used a filter (i'm using b+w >filters). i did some simple, empiracal tests: i shot the same scene at 2.8 >with and without the filter, with and without the hood, with and without >the lens hood, with and without the lens hood and filter. while the lens >hood and filter separately didn't cause noticeable vignetting (and, i've >got to admit, i didn't blow my prints up, or scrutinize the negs with a >loop, etc.), i noticed a slight darkening of the corners when the filter >and lens hood were used in combination at 2.8. i didn't follow through to >see if this existed only at 2.8, or if vignetting was still visible on >stopping down and, if to, to what extent at which aperture. has anyone else >had a similar experience/ran similar tests? You won't discover whether you have a vignetting problem in this manner, unless a very contrasty film is used. Lith film will do the trick. Much easier is to just look through the lens and see if the light rays are cut off prematurely, as I outlined in various other posts. * Henning J. Wulff /|\ Wulff Photography & Design /###\ mailto:henningw@archiphoto.com |[ ]| http://www.archiphoto.com