Archived posting to the Leica Users Group, 2001/07/30
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]A fascinating test. I'm especially amazed by how poorly the Nikkor 1.8/50 performs at all apertures. I actually have this lens, I think, somewhere, but I don't use it anymore; after seeing this, I'm not tempted to start using it again! I'm also somewhat surprised by how close the lenses are in the 90mm test. The Leicas are clearly superior at the other focal lengths, but at 90mm it looks like a wash to me. One other thing I noticed that is significant: none of these lenses, at any aperture, is resolving more than about 40 lp/mm. Indeed, if I downsample your actual-size scan to the size that would have been provided by an LS-2000 (with a maximum resolution of 2700 dpi), then upsample it again to the size provided by the 4000, the result looks identical to the original. In other words, the resolution of the image is no more than 53 lp/mm, and probably considerably less, around 40 lp/mm. It may be a film limitation, since the Summicron 90, at least, is supposed to be able to do far better than this (around 100 lp/mm, even out at the edges of the field, and even wide open). Provia starts to fall off pretty rapidly at 50 lp/mm, if I remember correctly. Yet more evidence that, for most purposes, you need never go beyond 2700 dpi. And the fact that this was all done on a tripod just underscores this point. And in the case of the Nikkor 50, even a hand scan of a one-hour print would probably extract just about all it can manage! I don't see any Leica Glow (tm), either. - ----- Original Message ----- From: "Paul Chefurka" <Paul_Chefurka@pmc-sierra.com> To: <leica-users@mejac.palo-alto.ca.us> Sent: Monday, July 30, 2001 03:29 Subject: [Leica] Some lens tests > I just finished putting upo some lens test pages that I hope will be more interesting than controversial :-) > > Leica lenses: 28 Summicron, 35 Summilux ASPH, 50 Summicron, 90 APO Summicron, Tri-Elmar > Nikon lenses: 50/1.8 AIS, 55/2.8 Micro, 85/2.0 AI > Cosina lens: Voigtlander 90/3.5 APO-Lanthar. > > Mostly shot at two apertures, 4.0 and 8.0. A complete description of the test methodology is on the opening page. Have at it, folks. > > http://members.home.net/chefurka/Photo/LensTests/LensTests.html > > > Paul Chefurka