Archived posting to the Leica Users Group, 1998/01/29
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Hi Erwin: Last year I performed extensive practical tests of most Leica 50mms for the M cameras (excluding the Noct). I believe that the later Rigid and Dual-Range 7-element Summicrons are a different design from the Collapsible (I didn't have a single-scale Rigid mount for comparison). They perform differently. The easiest way to see the performance differences is that they render out-of-focus areas quite differently and distinctly from each other; however, the differences can be seen in the in-focus imaging as well. Harold Merklinger was kind enough to e-mail me the text of his article proving the differences, and Jim Lager actually publishes two variant diagrams in his _History_ v. 2 covering lenses. Jim believes there were at least two designs. One point of order on which I differ with you is that I believe a difference in the physical size of an otherwise identical diagram qualifies as a different design. Several of the designs for the M vs. R range have identical diagrams, but the actual lenses perform differently because the R versions are physically larger. A concrete example is the 50mm Summicrons wide open--in field trials they do not perform identically, specifically with respect to spherical aberration. Also, I have had it explained to me by Zeiss designers that there are a number of design parameters that are not detectable by studying a cross-section. Incidentally, as a result of my tests I decided that the DR is the best 50mm Leica ever made--and this includes the current Summicron, an overrated lens IMHO--but for myself I prefer the Collapsible. I purchased one from Jim Lager at Tamarkin, one that had been rebuilt and recoated by a collector. Note to all: we are preparing a fine and extensive article for _PHOTO Techniques_ called "King of the Night: The Leica Noctilux" authored by Erwin. Look forward to it! Hi Danny--long time no see. I don't happen to agree with all of your specific assessments of lenses from various lines. However, I do agree that most lens lines have standout lenses and mediocre ones (some lines are more inconsistent than others); also, there are "family resemblances" between classes of designs that are sometimes stronger than the stamp of a marque. For example, Olympus 50/1.4 bears more resemblance to the Zeiss 50/1.4 than it does to its own Zuiko stablemate, the 50/2 Macro, owing to the close similarity of the Planar-type designs of the two f/1.4s. However, I stand by my general assessment of R lenses. Try this: make a field trial of the Leica R 35mm f/2 vs. the AF-Nikkor 35mm f/2. If you can find anything to complain about with the Nikkor, you're pickier than I am! An exemplary lens. Yet if you don't see the differences between it and the R lens, then...well, then you're lucky, because the Nikkor is cheaper and easier to use <g>. I think the difference is quite clear (at least with black-and-white film) and illustrates perfectly what I'm talking about. Again, each person has to decide for him- or herself whether it matters; ultimately, lens quality doesn't have very much to do with the success or failure of a photograph. To Dale: I agree about your assessment of German and Japanese engineers! I got a good laugh when Leica introduced their first point-and-shoot, when they said in their literature that they had sent several Germans to oversee the QC of the Japanese manufacturing line. As if the Germans could teach the Japanese anything about QC! The other way around, more likely--as anyone who's been watching the doings at Mercedes can attest. As to your question, there are two reasons why Leica lenses are different despite having no engineering advantage. One is that, because of their prestige, they are able to charge far more money for their finished products. All things being equal, any optical company could produce better lenses given more money to work with. (In fact, this helps explain why many companies' macro lenses are better than their high-speed normals--they can simply charge more for them, so they have more freedom to make them better.) If Pentax, for instance, could charge $1,700 for every normal prime and Leica could only charge $200, we'd all be "PUGgers." <g> Two is that design is, in part, an art. It is not entirely predicatable based on measurements. Every lens designer makes many compromises in the many choices that he is faced with. This is analogous to audio speaker designers--some design by measurement, some design by ear. The best use both. And the best also have specific _tastes_ in design strategies--look, for example, at the family resemblance of all Thiel speakers and that of all Martin-Logan speakers. You can tell a lot about which qualities each respective designer values, not to mention the specific engineering strategies each has chosen to devote his researches to. Over the years, Leica has been blessed by their early corporate determination to design at least in part "by eye"--that is, according to how the pictures look in practice. This has lead them to make different choices than the ones made by designers who are merely striving for the best balance of technical characteristics according to measurement. It's a commonplace that Leica lenses measure poorly at the widest apertures. Yet, in many cases, their designers have made choices that make actual images look _subjectively_ better even though they measure worse. If you doubt this, make an actual field trial between a 50mm Summilux-M and a Nikkor 50mm f/1.4 wide open. You'll see it with your own eyes. The Nikkor will be sharper; the Summilux image will be subjectively more pleasing. Finally there is the matter of inventive genius, which is something that surely pertains to engineering! I have a respect for Walther Mandler, for instance, that verges on awe. That fellow really knew what he was doing. Wow. <g> --Mike