Tony Smith Posted January 18, 2011 Share #1 Posted January 18, 2011 Advertisement (gone after registration) Does any member of the forum have experience of R lenses on nikon digital cameras? For example do the R lenses focus sharply as do the dedicated nikon lenses or is there a focus shift. I would be greatful for any information. Many thanks Tony Smith Link to post Share on other sites More sharing options...
Advertisement Posted January 18, 2011 Posted January 18, 2011 Hi Tony Smith, Take a look here R on nikon. I'm sure you'll find what you were looking for!
ho_co Posted January 18, 2011 Share #2 Posted January 18, 2011 Tony, I haven't personally tried R lenses on Nikons, but I have friends who are very pleased with their own conversions. The "focus-shift" thing is primarily a rangefinder phenomenon, simply because lenses for a reflex will be focused through the lens. Since SLR lenses will be focused wide open and then (usually) stopped down, the residual spherical aberration had to be closely controlled. Leica made use of the effect to gain some performance on rangefinder cameras, but with the true plane focus of the digital sensor, the focus shift is noticeable as a problem in some cases. In other words, no, focus-shift isn't a problem with R lenses on Nikon. Search the forum on "leitax." Several forum members have converted some R lenses to Nikon. Link to post Share on other sites More sharing options...
andybarton Posted January 18, 2011 Share #3 Posted January 18, 2011 I am very pleased with my R glass on my D700 Lots of shots on my website have been taken with this outfit. Link to post Share on other sites More sharing options...
RPS Posted January 19, 2011 Share #4 Posted January 19, 2011 I am very pleased with my R glass on my D700 +1 Link to post Share on other sites More sharing options...
berndr Posted January 19, 2011 Share #5 Posted January 19, 2011 In other words, no, focus-shift isn't a problem with R lenses on Nikon. Hello, when you focus with open aperture and you close the aperture, there can be a focus-shift with R lenses! When you focus with closed aperture you won't have focus-shift problems but focussing my be difficult because of the dark picture on the screen. There is no adaption with automatic aperture control avaible at the marked, this is another disadvantage. Regards, Bernd. Link to post Share on other sites More sharing options...
andybarton Posted January 19, 2011 Share #6 Posted January 19, 2011 If that's the case, how come this didn't affect R glass on R cameras? Focusing is always done at full aperture on an R camera. Link to post Share on other sites More sharing options...
ho_co Posted January 19, 2011 Share #7 Posted January 19, 2011 Advertisement (gone after registration) ... when you focus with open aperture and you close the aperture, there can be a focus-shift with R lenses! ... Focus shift is always a theoretical possibility, but as Andy said, how is it now noticeable when for forty years it wasn't? ... There is no adaption with automatic aperture control avaible at the marke[t].... Good point, Bernd! R lenses can be converted or adapted for use on Nikon and on Canon, but there is no automatic aperture linkage. Link to post Share on other sites More sharing options...
berndr Posted January 20, 2011 Share #8 Posted January 20, 2011 If that's the case, how come this didn't affect R glass on R cameras? Focusing is always done at full aperture on an R camera. The reason is that the light sensitive layer in the silicon sensors is thinner then in the classical film. The incoming light is absorbated somewhere in the film layer and generates a "point" on sensors the point must generated exactly in the thin sensitive layer, when not it results in an off focus picture. With the DMR you might see also focus shift. In digital rangefinder cameras (M8/9) you need much better adjusted finders then in the classical Ms. The reason for this is the same. The minimiced focus shift is in my opinion the main difference when you buy lenses which are optimiced for digital cameras (f.ex. the new M1.4/35 asph). On the other hand I have not many experiences with R glass on digital cameras, may be they are "traditionally" constructed with minimal focus shift and the thing we discuss is a academical thing. Regards, Bernd. Link to post Share on other sites More sharing options...
stunsworth Posted January 20, 2011 Share #9 Posted January 20, 2011 The reason is that the light sensitive layer in the silicon sensors is thinner then in the classical film. The incoming light is absorbated somewhere in the film layer and generates a "point" on sensors the point must generated exactly in the thin sensitive layer, when not it results in an off focus picture. With the DMR you might see also focus shift. I can't recall any problems ever being reported with the DMR and R lenses. I certainly never experienced it when I was using R lenses with various Canon cameras. Unless someone has seen it in practise this is a theoretical problem rather than an actual one. Link to post Share on other sites More sharing options...
andybarton Posted January 20, 2011 Share #10 Posted January 20, 2011 I have never had a problem with back or front focus on my DMR or my D700. I use R-lenses from the 1970s through to the 2000s. We would most definitely have had many threads here complaining about focus problems with the DMR if indeed this was a serious problem. Link to post Share on other sites More sharing options...
farnz Posted January 20, 2011 Share #11 Posted January 20, 2011 Bernd, I use (amongst other R lenses) an 80/1.4 Summilux-R on a Canon 5D MkII and I haven't noticed any focus shift with change in aperture. Pete. Link to post Share on other sites More sharing options...
lct Posted January 20, 2011 Share #12 Posted January 20, 2011 What's this story of focus shift? Never noticed any with my R lenses so far. Link to post Share on other sites More sharing options...
ho_co Posted January 20, 2011 Share #13 Posted January 20, 2011 When the DMR came out, people didn't suddenly discover focus shift in R lenses. When the M8 came out, focus shift became a hot topic. Bernd, good explanation, but as you said, in this case it's academic. Link to post Share on other sites More sharing options...
berndr Posted January 20, 2011 Share #14 Posted January 20, 2011 When the DMR came out, people didn't suddenly discover focus shift in R lenses. When the M8 came out, focus shift became a hot topic. Bernd, good explanation, but as you said, in this case it's academic. Finally I'm with you, the experiences of that many users gives obviously no hints for focus-shift problems with R line lenses in practice. So the optical construction was from the beginning on a very high level. I'm still hoping for the "adequate" digital Leica solution... The M wide angle lenses are constructed for a different environment (no retrofocus) this might be the reason for the bigger focus-shift problems. Kind regards, Bernd. Link to post Share on other sites More sharing options...
ho_co Posted January 20, 2011 Share #15 Posted January 20, 2011 Yes, Bernd, I agree. But there's another aspect on the M line that I think is more important: Since you're focusing with an external mechanism, the M designs in film days allowed Leica to get some extra performance mileage out of the undercorrected spherical aberration. By adjusting the lens for best focus wide open, and then allowing focus shift but keeping it within the limits of depth of field, Leica was able to optimize other parameters instead. As you said, when the M's went digital and lost the depth of film, that design practice became immediately visible. It's a design concept that could only have been applied to a rangefinder, since we never look through the lens. And now, the digital sensor requires at least reducing it drastically. Link to post Share on other sites More sharing options...
Mauribix Posted January 21, 2011 Share #16 Posted January 21, 2011 Focus shift is always a theoretical possibility, but as Andy said, how is it now noticeable when for forty years it wasn't? Are you forgetting Pixel-peepers? Those are the same who complained for years on Summilux 35 ASPH's focus shift problem. Link to post Share on other sites More sharing options...
Mauribix Posted January 21, 2011 Share #17 Posted January 21, 2011 While dogs are men's best friend... I guess this is photographer's worst enemy: Link to post Share on other sites More sharing options...
ho_co Posted January 21, 2011 Share #18 Posted January 21, 2011 Maurizio-- I like your judicious application of unsharp masking to the line that says "This text should be perfectly in focus." :D Link to post Share on other sites More sharing options...
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