Archived posting to the Leica Users Group, 1997/12/31
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]>All, > >The recent 75 1.4 Summilux M thread got me to thinking, "Just how good migh= t >that lens be?" Erwin certainly thinks its the bee's knees. But pawing down >through the lens test archive, I came across the Popular Photography August= 94 >review of the summilux (the only other one available, BTW), as well as anot= her >review of a lens I already have, the Nikkor 80-200 2.8 zoom. > >Here's the rub. The performance of both lenses at 2.8 is the same, with the >zoom tested at 80mm (both got a "C+"). How can this be? How can a single fo= cal >length Leica lens, two stops down from max (presumably improving performanc= e >significantly), equal the performance of a big zoom lens wide open? Shouldn= 't >the Leica blow away the zoom? How can this be? > >Some ideas... > >1) Pop Photo's lens testing procedures are out-of-whack >2) They tested the worst sample available of the 75 and the best sample >available of the zoom >3) The challenge of making a 75 1.4 at all necessarily includes optical >compromises, degrading potential performance at 2.8 in a lens of that speed > >Realizing that this isn't an apples-to-apples comparison in an infinite sen= se, >but concerned that two pictures taken by both lenses at 2.8 under the same >conditions would be indistinguishable, I'm longing for someone to tell me I= 'm >dead wrong. > >So, tell me. > >To quoth Roger, "Shields up!" > >David W. Almy >Annapolis, Maryland Looking at the same test: the 35 lux and 50 lux performed lower than the 75 at 2.8 and 22 mag. The 3 luxes were also tested in an earlier "Lab Report", pre-SQF, the percent contrast for the 75 was a bit higher in the plots. % flare was about .55 for the 50, .75 for the 75 and 2.0 for the 35. Mod Photo also tested the 75 in Mar '86 alongside the compact 90 'cron. The 75 rated excellent both center and corner at all stops. The 75 rated high contrast both center and corner at all stops. The 90 performed likewise as did the 35 'cron (7-element) and 28' rit (43mm filter size) in the wideangle tests for the M in the same issue. May '98 be Great! (my poetry for the day) Tom Kline