ho_co Posted September 8, 2011 Share #21 Posted September 8, 2011 Advertisement (gone after registration) ... I think Canon and Nikon are in the former group and Leica and Zeiss are in the latter. Actually, according to Erwin Puts, Leica publishes calculated figures and Zeiss measured features. He goes on to say that the calculated Leica MTF curves are almost identical to his measurements of the same lenses, due to the tight design/construction requirements of the Leica lenses. One thing you do need to watch across manufacturers is the lp/mm figures. Leica's MTF charts show contrast values for 5, 10, 20 and 40 lp/mm. Other manufacturers may not be so clear as to what the resolution figures are. Link to post Share on other sites More sharing options...
Advertisement Posted September 8, 2011 Posted September 8, 2011 Hi ho_co, Take a look here 35 Summilux ASPH vs. Canon 35 f/1.4 L. I'm sure you'll find what you were looking for!
adan Posted September 8, 2011 Author Share #22 Posted September 8, 2011 I'm pretty sure Photodo used 10/20/40 lppm for all their tests. Unfortunately their original site (which had that info - and also allowed side-by-side comparisons) is history except as preserved in the individual charts on the site I linked to. ____ John - the short version would be: For an ideal perfect lens, all the graphed lines would run horizontally right across the top - a perfect reproduction of the black-and-white lines on a test chart as pure black-and-white, at any resolution, in all parts of the picture. The more the lines drop lower on the chart, the lower the contrast of the lens. An excellent real-world lens can hit 70%-plus on the left with the lowest set of lines. 60%-plus is very good contrast (wide-open). The left side of the chart is the center of the image area, the right side is the corners (22.5 mm from the center, for 35mm lenses), so lines that sag on the right indicate a lens with fuzzy or low-contrast corner performance. As I said, MTF really measures "clarity" or "apparent sharpness" rather than resolution per se. I consider it a very rough approximation, at best, for determining how much detail can actually be captured. Link to post Share on other sites More sharing options...
IkarusJohn Posted September 8, 2011 Share #23 Posted September 8, 2011 BASed on that explanation (thank you), the Summilux-M 35/1.4 ASPH (FLE) looks deeply average. Especially considering it has been described as one of Leica's "best" lenses ... I think I prefer the image it produces to gazing at graphs! Cheers John Link to post Share on other sites More sharing options...
jaapv Posted September 8, 2011 Share #24 Posted September 8, 2011 diglloyd - Understanding optics - Understanding Modulation Transfer Function (MTF) My problem with MTF measurements is that they are a function of both resolution and contrast - and since I can usually add more contrast if it is missing (but cannot add more resolution if it is missing), I'm interested in raw resolution by itself. Example being the Summilux corner image @ f/1.4 above (baby on a Canon LCD). It is very low contrast (white wall a dull yellow-gray) but the edges are sharp. This would translate to a very low MTF for the corners (which is how most charts, including Leica's, show it) - where a lens with less resolution but more macro-contrast would score higher. In the all-film era, if one was shooting slides for projection, or negs for "straight" prints, with little recourse for post-processing, MTF as the standard made some sense (although I still preferred the old separate contrast and resolution tables). But today, it is pretty trivial to restore contrast locally. Below, I've fixed the contrast of the Summilux to let the resolution show its stuff (and for fairness, done my best to knock down the CA in the Canon image and equalize both for good contrast and color balance). Based soley on the MTF charts I've seen - the 35 Summilux ASPH is one of Leica's worst lenses. Based on real-world resolution, it is one of the best. I'll take the real world. Well the whole question is what you want to frame and hang on your wall - the MTF curves or the photograph Link to post Share on other sites More sharing options...
menos I M6 Posted September 8, 2011 Share #25 Posted September 8, 2011 Well the whole question is what you want to frame and hang on your wall - the MTF curves or the photograph How big a print size can you print the MTF chart from a 50 Lux ASPH on a M9? Thanks for this comparison, at first, the crops are quite shocking, but they indeed do represent exactly, what I felt, when I used my first Leica lens a few years ago and started consequently selling the shorter Nikon lenses, I started to use less and less. These Nikon lenses were no slouches, but indeed, the Leica lenses were so much better in comparison. Nowadays, I am actually going backwards, when MTF charts are a thing to go by. I am exploring more and more vintage lenses, to use on film and Leica digital. Link to post Share on other sites More sharing options...
pgk Posted September 8, 2011 Share #26 Posted September 8, 2011 Interesting comparison Adan. I actually own both these lenses but its never occurred to me to do a side by side comparison:eek:. Both are very good lenses. However one thing that I notice (from all my fast Canon lenses actually) is that wide-open they can suffer from significant green edges to the out-of-focus highlights behind the point of focus and magenta in front of it and sometimes this can actually be quite unpleasant (my 80 'lux was similar) and this colour edging can be intrusive even in relatively small sized uses. Its not only about resolution, MTF curves, and so on. I find my 35/50 'luxes much better in this respect. Just another observation, although I don't really see the two 35s as being comparable as one is big and bulky and the other is small and slight. No prizes for guessing my preference. Link to post Share on other sites More sharing options...
Steve Ash Posted September 8, 2011 Share #27 Posted September 8, 2011 Advertisement (gone after registration) The comparision reveals what everybody would anticipate and might please us as Leica users. "It is all about the lens". That statement is mentioned far too often in my point of view. Although I intially was surprised and enjoy the quality of Leica glass the main reason why I love my Leicas are the ergonomics and shooting experience with the Leica cameras. Regards, Steve Link to post Share on other sites More sharing options...
hoppyman Posted September 8, 2011 Share #28 Posted September 8, 2011 I don't know about Canon, Nikon or Zeiss but Peter Karbe from Leica Camera's optical design departmwent says that their published MTF figures are calculated... but they can prove that they are right But when comparing figures from different sources of course you need to be careful to see if they are measuring the same things and if their methodology (technique, sample variations, testing equipment etc) is the same too. They are, but if they are objective measurements of different things, they can be hard to compare The problem is that some companies publish calculated MTFs and some publish MTFs measured on real lenses. I think Canon and Nikon are in the former group and Leica and Zeiss are in the latter. Link to post Share on other sites More sharing options...
johnwolf Posted September 9, 2011 Share #29 Posted September 9, 2011 One point of comparison not mentiioned so far: price. $4995 vs. $1499. And, yes, DSLRs are relatively cumbersome, but on the 5DII the 35L always seemed to me about ergonomically perfect. Thanks for the comparison, Andy. John Link to post Share on other sites More sharing options...
batmobile Posted September 10, 2011 Share #30 Posted September 10, 2011 How dare you be so bold! I agree. This is the reason why I own Zeiss and CV lenses in addition to a couple of Leica ones, because very often, the difference in performance is irrelevant. I use my 24 lux when I need the speed. If not, I use my CV 25 f4 P. One very important point to consider is this: On B&W film, the Canon 35 1.4L will display more Leica glow wide open than the lux asph The comparision reveals what everybody would anticipate and might please us as Leica users. "It is all about the lens". That statement is mentioned far too often in my point of view. Although I intially was surprised and enjoy the quality of Leica glass the main reason why I love my Leicas are the ergonomics and shooting experience with the Leica cameras. Regards, Steve Link to post Share on other sites More sharing options...
Peter H Posted September 10, 2011 Share #31 Posted September 10, 2011 Well the whole question is what you want to frame and hang on your wall - the MTF curves or the photograph :D Link to post Share on other sites More sharing options...
mmradman Posted September 10, 2011 Share #32 Posted September 10, 2011 Well the whole question is what you want to frame and hang on your wall - the MTF curves or the photograph Top post. Link to post Share on other sites More sharing options...
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