Hi dear all! Since I'm not an expert in optics and lens design, and I'm just comparing via web reviews, here at this forum, etc. the lens quality differences between the Leica M and R series, I'd like to post to your attention a statement that I want to understand better; at http://www.imx.nl/photosite/Topics/topic02.html the reviewer wrote: "But its small body [refers to Leicas series M], and compact lenses (compromised in optical quality compared to the best R-lenses because of volume considerations) allow a different style of photography, etc., etc.
What the heck means "volume considerations"? -- That's it, any opinion about it?
Ciao -- Marco.

BTW: what do you prefer, Leica M6 TTL (and its lenses) or Leica R 6.2 or 7 (and its lenses)?

-- Marco Maria Colombo (mcolombo@iol.it), October 02, 2001

Answers

Either you're misquoting this reviewer, or they review for the "Moron Journal."

-- Leicaddict (leicaddict@hotmail.com), October 02, 2001.

The person who operates that website is of the opinion that the lens- size limitations of the M (I infer, with respect to obscuring the viewfinder--I can't think of any other reason, since the 90/2, 75/1.4 and 135/2.8 are certainly the size equal of comparable R lenses) somewhat inhibit the lens designers' freedom to correct aberrations. This is an interesting theory, however it is also at least partially contradicted by his own test results, to wit: the 1st-version 19/2.8 Elmarit-R, with an absolutely gargantuan 82mm front element is reviewed with much less praise than the approximately contemporary 1st 21/2.8 Elmarit-M with its 60mm front. Likewise he states (in his book) that the current 28/2.8 Elmarit-R (E55) is comparable to the previous (E49) version of the 28/2.8 Elmarit-M, and somewhat behind the current (E46) version. Of course, if Leica were to try and design a 100/2.8 APO-Macro-Elmarit or a 180/2 APO-Summicron for the "M", not to obscure the viewfinder, they might have a problem but the point is, after all, moot. Note that even without size restrictions Leica has never made a Noctilux in R mount.

-- Jay (infinitydt@aol.com), October 02, 2001.

Hi again Marco!

I'm not sure I can answer your question perfectly but here we go: I am not an expert here either but I see two things: (a) The lenses of Leica's Rs ARE more volumetric because they ARE larger than the corresponding Ms. The Ms are IMO not compromised in the sense that they are practically almost as good as the Rs, the Ms ARE just as good, maybe sometimes even better than the Rs, ALTHOUGH they are smaller. (b) Erwin's writing there is (again IMO) basically good, roughly complete, even subjective, although as usual somewhat dry. What he is trying to say, I think I understand, and that would be why I got rid of all my Rs (Nikons) over more than 20 years in order to get into my present day M6 TTL stuff. That means simply that I have gotten off the size and "normality" and opportunities and automation of an R in order to get into the simplicity and durability and timeless perfection of an M. (I don't even think I have to say I'm sorry, but there is, here chez Erwin, a sort of transcribed or figurative or metaphorical sense, as in the delegation that the M's lenses may be smaller, but the M's world is still bigger. I think that's something he is saying. Whew. Sorry for shouting so often, Marco.

Mike

-- Michael Kastner (kastner@zedat.fu-berlin.de), October 02, 2001.

I interpret Erwins point here to be fairly straitforward: Simply stated he is defending the argument that the M has superiority in "stealth" or "street" style photograhy over the R (or any other SLR) because of its diminuitive size. The M's compact size allows for a lower level of "intervention" between photographer and subject in the picture-taking process than does an SLR - even if subjects are aware of you, they don't take you as seriously because the camera does not look professional... In his defense, he did state that both systems offer excellent optics, yet each system has their individual strengths and weaknesses.

-- Jack Flesher (jbflesher@msn.com), October 02, 2001.

I don't understand that statement at all, especially if it were written by Erwin. The Leica M lenses are lens for lens BETTER than the current R version, the single exception being the 50/1.4 Summilux (which was recently re-designed for the R system). Erwin even makes this point repeatedly in his evaluations of Leica M lenses: eg., 24/2.8 M Elmarit far better than R, 35/1.4 ASPH better than R version, 75/1.4 Summilux better than 80/1.4 Summilux R, 90/2.0 Apo- Summicron far better than R version, 135/3.4 Apo-Telyt better than R etc, etc. As far as I have seen by any lens tester, the current generation of newly designed M lenses are the best, unsurpassed by any maker, even Leica R. That statement makes no sense.

Moreover, the Leica M bayonet diameter is significantly smaller than the Leica R, because Leica M does not require an auto-diaphragm. The Leica M lenses require less back-focus due to the absence of a reflex mirror. These are volumetric considerations that FAVOR the design of M lenses. If that review was written by Erwin, perhaps someone should ask him why it contradicts his many lens reviews that compare the M lens to the concurrent R version and conclude the M design is superior.

-- Eliot (erosen@lij.edu), October 02, 2001.

I think Erwin was specifically referring to the 50 1.4 designs, because that is the one focal length/aperture combo where a) the R lens is sharper/contrastier and b) viewfinder constraints prohibit adapting the R design for use on M bodies - the 60mm front filter size would be nearly as big as the Noctilux. I know someone recently quoted Leica people as saying it was not "technically feasible at this time" to make the new design in M-mount.

Other than that, on the whole the Leica-M lenses are equal to or better than the R lenses where there are equivalents - witness that the M 90SAA is about to be issued as an R lens as well. But it's very close - the 180 Apo-Elmarit lens is better (according to Leica's MTF charts) than the 135 Apo-Tele-Elmar f/3.4, and the 100 macro-R runs neck and neck or slightly ahed of both the M6 90s.

But in the following focal lengths the M lens all come out ahead: 19/ 21 f/2.8; 24 f/2.8, 28 f/2/2.8; 35 f/2/1.4; 50 f/2; 75/85 f/1.4.

At this point for reflex I have one old Nikon F body with no lenses, shoot everything with Leica-M4-2/M4-P and 21/28/35/90, and feel no need whatsoever to change to anything else within that lens range. If I ever need longer I would almost certainly just get a 180 for the Nikon.

-- Andy Piper (apidens@denver.infi.net), October 02, 2001.

Andy,

That may be true of the 50/1.4 Summilux, though I haven't heard any comments on the subject from Leica. And that is not to say they couldn't re-design the 50/1.4 specifically for the M system and make an even better lens. Erwin's comments were in the context of a general discussion of M vs R systems, and were not linked to any particular focal length. That's why I was so surprised reading them on the photodo.com website.

BTW, you can't compare the MTF charts from lenses of two different focal lengths (as in the 135/3.4 vs 180/2.8 APO lenses). The angles of acceptance of these lenses are significantly different. The wider the angle of acceptance (135 mm lens), the harder to achieve uniformly high correction across the field, especially at the edges. That is why Leica is able to get such high and uniform performance across the field for their 180 mm and longer APO lenses. Other manufacturers have been able to do the same.

-- Eliot (erosen@lij.edu), October 02, 2001.

Eliot: Yeah, I think Erwin was generalizing from the particular (the 50 'lux) without much justification - as we agreed, MOST of the other M lenses surpass their R equivalents.

RE the 135 vs. 180. I actually was reading the MTF curves for the CENTER of the image, where the M-135-APO gets about 72% at 40 lppm, while the R-180-APO gets 82% at 40 lppm. I didn't pay a lot of attention to the corners, although both seemed to have fairly flat, consistent curves at least compared to wider lenses (illustrating your general point very clearly).

Best, Andy

-- Andy Piper (apidens@denver.infi.net), October 03, 2001.

"Either you're misquoting this reviewer, or they review for the "Moron Journal." "

Believe me, Leicaddict (interesting name, BTW), Erwin is far from being a moron. Sometimes it takes a while to figure out what he means, but it's generally worth it.

-- rob (rob@robertappleby.com), October 03, 2001.

Hmmm, now something absolutely positive today: Best phrase of all, here, Rob.

-- Michael Kastner (kastner@zedat.fu-berlin.de), October 03, 2001.

Front element size is a limiting factor for M cameras. I have heard this from both Leica, Erwin and others. The Leica f/2.8 wide angles are the best in the business but everyone else has f/1.4s. There are many times I would gladly trade "micro-contrast" in the edges for more light vacuuming power.

Cheers,

-- John Collier (jbcollier@powersurfr.com), October 04, 2001.

John,

I heard that comment too, but I have to admit I don't understand it. Leica made a 28/2.0 Summicron-ASPH better, in fact, than the 28/2.8 Elmarit, yet no larger in any dimension. I have this lens, it is really quite excellent. They must be referring to the volume of the lens with a rectangular lenshood, since the lens itself is nowhere close to obstructing the viewfinder. Perhaps a 28/1.4 M lens with the hood would obstruct too much of the viewfinder, but I would think a lens itself could be designed that would not obstruct significantly when used sans lenshood.

I have also heard the comment from Leica that they could not make a 50/1.0 Noctilux in the R configuration. Other than it being larger and heavier, on account of the autodiaphragm and larger bayonet mount diameter, what would stop them?

There are only two SLR wide angles of 28 mm or less that have apertures of F/1.4: the Nikkor autofocus 28/1.4 and the Canon EF mount 24/1.4-L (which is an update of the older Canon FD mount 24/1.4- L lens). [Canon has an EF 35/1.4, but Leica offers the F/1.4 Summilux-ASPH in the 35 mm focal length.]

I don't think the Nikon 28/1.4 and Canon 24/1.4 offer much in the way of performance at F/1.4. Perhaps Leica feel that they could not currently design a lens of 28 mm or smaller focal length that could do justice to the Leica reputation at F/1.4?

-- Eliot (erosen@lij.edu), October 04, 2001.