Archived posting to the Leica Users Group, 2000/07/22
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]>[Ok, I give up on AOL] > >Do we all need an ND8x (0.9) filter?! > >This is a problem I was thinking about when I started shooting the hell >out of my 35/2 Summicron last week. People always rail about using a >skylight or UV because it "wrecks the optical system." I think there is >one filter that actually improves the optical output. > >Don't we all need an ND8x? > >If Leica lenses like the Summicron are diffraction-limited at f/8 and >smaller (per Erwin Puts), don't we all need an ND8x filter with most >lenses? On a sunny day, the exposure should be roughly (with ISO >100/125 film - negative): > >f/16 and 1/125 > >To get to f/5.6 we need to increase the shutter speed to 1/1000. This >doesn't really work with the older cameras (like screwmounts) unless >they are consistently tuned-up. (Query: so why does Leica make 35/2 and >50/2 SM lenses, unless they anticipate a faster shutter somewhere - or >is it a marketing gimmick - or anticipated to be "shared" with an M6?) > >But suppose we start using 400 film (like, say, Tri-X or TMY. Probably >better to think color for the resolution) > >Then we need 1/4000 sec. > >But if we're shooting portraits on 400NC with an Elmarit, Nikkor, >Hexanon or Jupiter 85/90, we want f/2.8 or 4 > >Then we need 1/8000 sec or 1/16000 sec, unless we bring that down with a >0.9 to get 1/1000 or 1/2000. > > > ------------------------------------------------------------------------ >Dante Stella >http://www-personal.umich.edu/~dante What you need are two bodies. Load one with APX 25 and your need for high shutter speeds disappears, sunshine or not. - -- Christer Almqvist D-20255 Hamburg, Germany and/or F-50590 Regnéville-sur-Mer, France