CheshireCat Posted September 10, 2015 Share #141 Posted September 10, 2015 Advertisement (gone after registration) Without concrete numbers it is baseless to claim that glass in front of a sensor prevents us from having lens that behave comparably on film and on digital as far as the effects of refraction. I think there is a very useful comment from Mike Brassey below the mentioned text by Dr Caldwell http://www.lensrenta...-adapted-lenses This is getting ridiculous. You have concrete numbers in the article I cited, which clearly shows the difference on the optical bench. I don't know who this Mike guy is, but I don't think his [long] comments make much sense. It should be enough to say that film thickness is not measured in mm like sensor cover glass, and the refraction between layers in film, if any, would be minimal. Link to post Share on other sites More sharing options...
Advertisement Posted September 10, 2015 Posted September 10, 2015 Hi CheshireCat, Take a look here Leica's organic rendering versus plasticized Sony 7RII. I'm sure you'll find what you were looking for!
CheshireCat Posted September 10, 2015 Share #142 Posted September 10, 2015 I am well aware of the optical properties of a planparallel piece of glass. Finally, now you are. Leica is looking for solutions in sensor design, not lens design. Yes. But you cited the mysterious Karbe's interview to claim the exact contrary. That makes Peter Karbe's statement the simple truth, not spin. Still waiting for the link to this mysterious interview. A random statement taken out of the original context is not a valid citation. Link to post Share on other sites More sharing options...
jaapv Posted September 10, 2015 Share #143 Posted September 10, 2015 Finally, now you are. M first long post on the subject (related to a protective filter discussion) dates about eight years back. As a newbie, you can be excused... Yes. But you cited the mysterious Karbe's interview to claim the exact contrary. ??? Still waiting for the link to this mysterious interview. A random statement taken out of the original context is not a valid citation. Read the forum regularly and be enlightened Link to post Share on other sites More sharing options...
jaapv Posted September 10, 2015 Share #144 Posted September 10, 2015 This is getting ridiculous. You have concrete numbers in the article I cited, which clearly shows the difference on the optical bench. I don't know who this Mike guy is, but I don't think his [long] comments make much sense. It should be enough to say that film thickness is not measured in mm like sensor cover glass, and the refraction between layers in film, if any, would be minimal. In what unit would you other than mm, microns or whatever would you measure thickness then? Arcseconds ? Link to post Share on other sites More sharing options...
edwardkaraa Posted September 10, 2015 Share #145 Posted September 10, 2015 I think it is quite obvious that the film is the actual sensor and it does not have a thick sheet of glass in front of it that causes the astigmatism with oblique rays. Link to post Share on other sites More sharing options...
mjh Posted September 10, 2015 Share #146 Posted September 10, 2015 Off the top of my head I cannot provide a verbatim Karbe quote but I am pretty sure Peter Karbe would confirm that his M lenses are intended to be used with digital and film-based Ms and are designed accordingly. That doesn’t deny the fact that film and sensor behave quite differently. Still the different requirements they pose can be reconciled. Link to post Share on other sites More sharing options...
mgrayson3 Posted September 10, 2015 Share #147 Posted September 10, 2015 Advertisement (gone after registration) I find the Sony colors too uniform by default. It's a color-by-number look: all blues are the same blue, all wood is the same color, all skin. It's eerie. Fortunately, it can be improved in post, but requires going back to a flat, low-contrast image and building up a natural look. Leica's defaults are much more natural (at least the M and S, the Q is a bit oversaturated by default). The A7II is currently my main system, because I have great difficulty focussing the longer M lenses, but I (much) prefer the output of the M9 at lower ISO. Best, Matt Link to post Share on other sites More sharing options...
01af Posted September 10, 2015 Share #148 Posted September 10, 2015 I know I'm late to the party ... but when looking at the processed JPEG crops from the inital post as well as at the two raw files provided via Dropbox then I find the Sony image better in all aspects—resolution, colour fidelity, colour separation, dynamic range, shadow detail, overall appearance. In particular, it is totally mind-boggling how much sharpening the Sony raw file can take without falling apart or looking fuzzy while at the same time it also looks amazingly good with no sharpening at all. Never experienced something like that before. The Leica is the better camera (for it's a rangefinder and takes M lenses natively ) but the Sony produces the better image files. If one camera's pictures have a more organic look than the other's then it's the Sony's. Link to post Share on other sites More sharing options...
wattsy Posted September 10, 2015 Share #149 Posted September 10, 2015 heritage lenses Is that what they are called? I'll have to remember that one. If you can cut between all the tiresome bickering (by the usual contributors), this question of whether some lenses are more suited to film or digital is actually quite interesting and something I think many of us have underestimated in the years since the M8 has made the question relevant. My personal take is that many of the venerable M lenses designed in the film-only era (including current lenses like the 28 Summicron introduced in, I think, 2000 and the 35 Summicron-ASPH from the early 1990s) are much better suited for use on film cameras. These are fine lenses on any medium but are sensationally good with film where the qualities and optical character really shine. IMO they are a little wasted (and sometimes problematic) on the digital bodies. Link to post Share on other sites More sharing options...
Adam Posted September 10, 2015 Share #150 Posted September 10, 2015 This is getting ridiculous. You have concrete numbers in the article I cited, which clearly shows the difference on the optical bench. I don't know who this Mike guy is, but I don't think his [long] comments make much sense. It should be enough to say that film thickness is not measured in mm like sensor cover glass, and the refraction between layers in film, if any, would be minimal. The article is interesting to read, but obviously hard for some. It was about effects of different types of glass vs no glass in front of a sensor. No measurements of film. Thus you cannot use it to make general statements about sensors emulating film. All we know is that glass in front of a sensor make lens behave differently, and thickness is a factor. In some cases lens behave worse with glass, in some cases, as with the 35mm cron, they behave differently. There was no comparison with film, just glass vs no glass, and 2mm thickness vs 4mm thickness. Without concrete data it is impossible to say what the comparisons with film are. There is no data that film layer refraction is irrelevant (equal to air). Thickness of film is not the only contributor to refraction, density is another. The comments by Mike below the article actually make more sense than what I read here, opinion masquerading as fact. Link to post Share on other sites More sharing options...
CheshireCat Posted September 10, 2015 Share #151 Posted September 10, 2015 Without concrete data it is impossible to say what the comparisons with film are. People have been shooting film with Leica M lenses since 1954. After 61 years, I think we have enough "data" to compare with film, without the need to bring lens designers into the discussion. There is no data that film layer refraction is irrelevant As there is no data that photography is not stealing the subject's soul Link to post Share on other sites More sharing options...
Adam Posted September 10, 2015 Share #152 Posted September 10, 2015 People have been shooting film with Leica M lenses since 1954. After 61 years, I think we have enough "data" to compare with film, without the need to bring lens designers into the discussion. No we don't. We have 61 years worth of pictures. We are talking about refraction, not aesthetics. Lens designers know more about refraction than most photographers as is evident from the comments above. As there is no data that photography is not stealing the subject's soul There is no reason to suspect it does. False analogy. Film is a different medium from air so it triggers refraction. That is a fact. This means that our starting assumption must be that film refraction is relevant in the comparison with glass. The assumption can only be rejected with empirical data, which is lacking in the post. Basic reasoning. Try harder. Link to post Share on other sites More sharing options...
CheshireCat Posted September 10, 2015 Share #153 Posted September 10, 2015 Film is a different medium from air so it triggers refraction. That is a fact. It is also a fact that when you jump, you slightly move the earth. But not by much. The same is valid for refractions in film layers, as we are talking about emulsion thickness of microns vs millimeters for sensor cover glass. But take your time to collect actual data to prove the contrary. Random citations from Kodak employees, or Joe guy posting in some film forum may also help Link to post Share on other sites More sharing options...
jaapv Posted September 10, 2015 Share #154 Posted September 10, 2015 Well, microns... 0.17 mm average film thickness, the emulsion being only part of that, but as light is in nanometers, that is still relevant. Link to post Share on other sites More sharing options...
pgk Posted September 10, 2015 Share #155 Posted September 10, 2015 Well, microns. 0.17 mm average film thickness... Film wasn't flat....... Link to post Share on other sites More sharing options...
Adam Posted September 10, 2015 Share #156 Posted September 10, 2015 It is also a fact that when you jump, you slightly move the earth. But not by much. Yep. And when you are measuring the sensitivity of a seismic sensor, jumping next to it matters. It is not scale of the effect but its impact on the comparison being made that matters. The same is valid for refractions in film layers, as we are talking about emulsion thickness of microns vs millimeters for sensor cover glass. No it is not. You simply do not know, unless you have measured the effect. Take a micron of material with a high refraction index and compare it with a mm of material with a low refraction index. Based on just thickness you would end up with the wrong conclusion. Thickness is just one variable of the equation. But take your time to collect actual data to prove the contrary. Random citations from Kodak employees, or Joe guy posting in some film forum may also help I see you are still missing the point. I don't have to prove that refraction on film is relevant. Film is not air, thus its refraction is a possible confound. You need to show that it is irrelevant in order to make your claim. To do that you need controlled experiments like the ones carried out on glass in the article you cited. Folksy misplaced analogies do not count. All you get is a false assumption that a sensor without glass is a good predictor how film behaves. Random citations from Kodak employees, or Joe guy posting in some film forum may also help Actually, I used a post made to an article which you recommended. For which I thank you. However, I always find it amusing when anonymous posters disparage comments from people like Mike Brassey who actually sign their posts. I guess a specialist in optics is less credible than a fading cat. Must be the cattitude Link to post Share on other sites More sharing options...
CheshireCat Posted September 10, 2015 Share #157 Posted September 10, 2015 I guess a specialist in optics is less credible than a fading cat. Must be the cattitude I may agree on this. Most people give importance to... appearance. Link to post Share on other sites More sharing options...
Adam Posted September 10, 2015 Share #158 Posted September 10, 2015 I may on this. Most people give importance to... appearance. You may, but only on the assumption that the lack of it is more credible Link to post Share on other sites More sharing options...
tgm Posted September 10, 2015 Share #159 Posted September 10, 2015 Well, microns... 0.17 mm average film thickness, the emulsion being only part of that, but as light is in nanometers, that is still relevant. I suggest that you aks a physics, an expert in optics and he will tell you the following. The wavelenght of the light has no effect, what count is the effecive optical pass in the cover glass which is (n-1) l* tan(alpha) where n is the index of refraction and l thickness of the the cover glass and alpha the incidence of the light ray. What are the solutions for best resolution? 1) n=1, means no cover glass/ film, x=0, extremly thin cover glass, alpha =0, means extremly telecentric design. In summary, there is a new parameter for the lens designer, the effective light pass in the cover glass. The only way design lenses working with very differnt cover glas is extremley telecentric, resulting in huge lenses for full frame sensors. Link to post Share on other sites More sharing options...
jaapv Posted September 10, 2015 Share #160 Posted September 10, 2015 The only way design lenses working with very differnt cover glas is extremley telecentric, resulting in huge lenses for full frame sensors. Which is not an option for rangefinder lenses as they should be as small as possible. Reason this cannot be a consideration for Leica M lenses. Thus Leica uses as thin a cover glass as possible, resulting in IR problems, cracked cover glass, corrosion by using coating instead of a sandwich, moiré by eliminating an AA filter, etc. Meaning they adapt the sensor to the limit of technical possibilities, not the lens design. And they are handicapped by having to use a narrow M mount as well for the sake of retrocompatability. Link to post Share on other sites More sharing options...
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