Archived posting to the Leica Users Group, 1997/03/14
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Adrian Tanovic@GRN 03/14/97 08:31 AM Interesting topic. Leica also claims it's Focotar 40mm/f2.8 is optimized at f5.6, which is, as you say, two stops from wide open. I find I prefer slightly longer exposure times so I generally use it at f8, sometimes even f11, with no ill effects that I can detect. I don't find negative flatness to be a big issue for 24x36mm negatives unless they've been improperly dried or are for some other reason badly curled. Indeed, glassless negative carriers seem to produce a degree of flatness which is more than adequate at f5.6 and smaller, and eliminate the problem of dust on the glass into the bargain. By the way, Steven, you mention you use the Schneiders. I wonder if you have any experience with the Apo-Componon HM series? This might be of interest to the group since the Apo 40mm f2.8 (in the Leica screw mount) is one of the few quality alternatives to the Focotar 40mm for V35 users. Like the Focotar, it is also a modified Gauss type lens, but of more recent design, containing 7 elements in four groups. Best, Adrian Tanovic Tokyo >From: Steven Blutter <sblutter@worldnet.att.net> >Date: Thu, 13 Mar 1997 17:13:10 -0600 >Subject: Re: OFF TOPIC--Englarging lens questions > >>Alan Bearden wrote: >> >> At 06:55 AM 3/13/97 -0400, you wrote: >> >What, if any, practical effect does the aperture setting of a enlarging >> >lens have? If you print a negative at f/16, will you have a greater >> >"depth of field" in the sense that if the negative is not perfectly flat > >in the carrier, that area of the negative will print sharper than if you > >printed the same, >not-perfectly-flat negative at f/2.8? >> > >> >Thanks for your thoughts. >> > >> >-----Yes! > >again, i'm no lens guru, but having taken the advise of many greats over the years and plain old trials, most lenses are at their sharpest 2 -3 >stops from OPEN. yes, logically the depth of field would seem a >benefit, but enlarging lenses are very nice in that they don't want you >to have 3+ minute exposure times, thereby losing any benefit you might >have had. my schneiders are definatly sharpest at 2 from open, and even >1 from open is damn sharp, right to the edge on 16 x 20's. >please make sure you've got everything calibrated (level). everything!