CheshireCat Posted February 27, 2015 Share #121 Posted February 27, 2015 Advertisement (gone after registration) http://www.onsemi.com/pub_link/Collateral/KAF-18500-D.PDF Page 14 for the M9 response curves. Page 15 for the QE curve as a function of illumination angle. Thanks, but the graph shows that IR is well filtered out. I suppose it is because Leica used a different IR-cut filter than the S8612 used in that datasheet. Link to post Share on other sites More sharing options...
Advertisement Posted February 27, 2015 Posted February 27, 2015 Hi CheshireCat, Take a look here CCD vs CMOS: Can you tell which is which?{merged}. I'm sure you'll find what you were looking for!
CheshireCat Posted February 27, 2015 Share #122 Posted February 27, 2015 Huh? The colour comes from the dyes in the Bayer filter and subsequent interpolation, not from the sensor, which is a monochrom device. The secret to beautiful colors Add to that the IR-cut filter and coatings. And obviously the lens. Furthermore, you are right that the color comes from the Bayer filter, but are we sure that different sensors will have the exact same frequency response graph to different light frequencies (i.e. Bayer filter excluded) ? Link to post Share on other sites More sharing options...
CheshireCat Posted February 27, 2015 Share #123 Posted February 27, 2015 Could you Dropbox one of the offending files? Will try to find them later. They are even worse than the example in lct's last post. Link to post Share on other sites More sharing options...
jmahto Posted February 27, 2015 Share #124 Posted February 27, 2015 Not my experience or anyone else who's paying attention. You really think you can make the 50 Lux or 28 cron from the 240 look like it came from an M9? I have both these lenses and I did pay attention carefully (while deciding to switch). I had both M9 and 240 for a month and I have real life photographs from both these lenses on both these cameras and there is no difference (apart from the usual diff between M240 and M9 sensor output). I get the same sharpness across the frame with 28 on 240 as I got with M9. Maybe you are referring to Tim Ashley's test of 28cron on M240. My experience differs from him. Sometimes you have to test and decide for yourself. Link to post Share on other sites More sharing options...
IWC Doppel Posted February 27, 2015 Share #125 Posted February 27, 2015 Will there be a Part 3 or is it time for finding out what's what Link to post Share on other sites More sharing options...
Lenshacker Posted February 27, 2015 Share #126 Posted February 27, 2015 Thanks, but the graph shows that IR is well filtered out. I suppose it is because Leica used a different IR-cut filter than the S8612 used in that datasheet. The M9 uses the S8612 cover glass. This is well known on the M9 forum and is the cause of the well-published issue with the cover glass. The IR is well filtered out, optically the S8612 very efficient.. According to Jaap, who owns an M240 and is a very experienced M9 user, The M240 shows higher levels of IR bleed. If anyone that owns both an M9 and M240 would take a picture of a Wii light bar or TV remote using the same lens and settings, we'd have a valid comparison. As others have learned, do your own measurements. Link to post Share on other sites More sharing options...
Lenshacker Posted February 27, 2015 Share #127 Posted February 27, 2015 Advertisement (gone after registration) Add to that the IR-cut filter and coatings.And obviously the lens. Furthermore, you are right that the color comes from the Bayer filter, but are we sure that different sensors will have the exact same frequency response graph to different light frequencies (i.e. Bayer filter excluded) ? Look at the data sheet for a KAF-1600 vs a KAF-1602e. Different detectors have different spectral responses independent of the color mosaic filters. Among other factors, it depends on the specific chemistry of the detector, the depth of the pixel, and number and placement of the collectors. Deeper pixels absorb more IR, longer wavelenghts of light get absorbed deeper in the material. Various dopants change the spectral response, individual manufacturers have their own recipes, often protected by patents. http://www.google.com/patents/US5804845 Link to post Share on other sites More sharing options...
pgk Posted February 27, 2015 Share #128 Posted February 27, 2015 Sorry, but that's a pipe dream. It just isn't possible unless you use the same sensor. The colour comes from the dyes in the Bayer filter and subsequent interpolation, not from the sensor, which is a monochrom device. So is a consisten workflow possible or not? We do seem to be having a circular argument/discussion here and getting nowhere pretty quickly. Link to post Share on other sites More sharing options...
Lenshacker Posted February 27, 2015 Share #129 Posted February 27, 2015 So is a consisten workflow possible or not? We do seem to be having a circular argument/discussion here and getting nowhere pretty quickly. Very little actual information has been brought forward regarding the M240 sensor spectral response, IR bleed, and efficiency with regard to illumination angle. Of those: the IR Bleed problem with the M240 sensor probably makes a consistent workflow more difficult. Link to post Share on other sites More sharing options...
CheshireCat Posted February 27, 2015 Share #130 Posted February 27, 2015 If anyone that owns both an M9 and M240 would take a picture of a Wii light bar or TV remote using the same lens and settings, we'd have a valid comparison. As others have learned, do your own measurements. Agreed. This is certainly an interesting test, although the Wii bar and TV remotes cannot be used to check the entire IR spectrum. The weird skin colors with the M9 in some (but not all) kinds of artificial light, makes me think the issue may be triggered only by some frequencies in the IR band. Too bad my M9 is 10000 Km away from my M240. Anyone else has both at hand ? Link to post Share on other sites More sharing options...
thighslapper Posted February 27, 2015 Share #131 Posted February 27, 2015 Furthermore, you are right that the color comes from the Bayer filter, but are we sure that different sensors will have the exact same frequency response graph to different light frequencies (i.e. Bayer filter excluded) ? It doesn't matter. There is calibration applied to produce the colour profile the manufacturer wants. Link to post Share on other sites More sharing options...
Lenshacker Posted February 27, 2015 Share #132 Posted February 27, 2015 Agreed. This is certainly an interesting test, although the Wii bar and TV remotes cannot be used to check the entire IR spectrum. The weird skin colors with the M9 in some (but not all) kinds of artificial light, makes me think the issue may be triggered only by some frequencies in the IR band. Too bad my M9 is 10000 Km away from my M240. Anyone else has both at hand ? Leica M9, ISO160, Snow with Noon sun, 1/3000th second at F8 with no filter; 1/12th Second, F8, Wratten 88a filter. The 88a cutoff is 720nm, the S8612 data sheet indicates 2.9E-3 transmission at 720nm . If I can find my 87c, I'll do another test. I use the 88a with a full-spectrum camera, can't find the 87c- might have given it away... Link to post Share on other sites More sharing options...
dfarkas Posted February 27, 2015 Author Share #133 Posted February 27, 2015 Will there be a Part 3 or is it time for finding out what's what Part 3 wrap up, reveal and conclusion is in the works. Should be up early next week to give folks a bit more time over the weekend to cast their votes. Got plenty of votes on Part 1. The votes for Part 2 are still coming in. Thanks! Link to post Share on other sites More sharing options...
jaapv Posted February 27, 2015 Share #134 Posted February 27, 2015 Never got skin tones like this with the M240. Was an early M9 pic though.http://lctphot.smugmug.com/photos/3900877352_wJTGf3J-D.jpg (7 MB file) But does it need to be that way? 20 sec PS (PPW Skin desaturation, back to RGB, Red lightness +10, general lightness -7, general saturation -5), and that is just one quick interpretation: Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/241543-ccd-vs-cmos-can-you-tell-which-is-whichmerged/?do=findComment&comment=2771760'>More sharing options...
Lenshacker Posted February 27, 2015 Share #135 Posted February 27, 2015 Of course the other explanation for red faces is simply that it is a reflection off the Red Dot on the front of the camera. Skate and Fun Zone The Red Dot is everywhere. Link to post Share on other sites More sharing options...
IWC Doppel Posted February 27, 2015 Share #136 Posted February 27, 2015 But does it need to be that way? 20 sec PS (PPW Skin desaturation, back to RGB, Red lightness +10, general lightness -7, general saturation -5), and that is just one quick interpretation: A great picture, I'd forgive colour hues anyway Link to post Share on other sites More sharing options...
jaapv Posted February 27, 2015 Share #137 Posted February 27, 2015 Not mine! LCT's I just did a bit of PP to remove the Heinz 57 Varieties effect. Link to post Share on other sites More sharing options...
IWC Doppel Posted February 27, 2015 Share #138 Posted February 27, 2015 Nice piccy LCT Link to post Share on other sites More sharing options...
Lenshacker Posted February 27, 2015 Share #139 Posted February 27, 2015 "Whoops, the M9 exposure meter has a much different response than the sensor"... The IR sensitivity of the exposure meter of the M8 is close to the KAF-10500. The IR sensitivity of the exposure meter of the M9 is close to the M8 sensor, not the one actually used in the camera. New Numbers- M9, Snow, Bright Sun, but ~3:00pm. ISO 160 1/2000th sec, F8 With 88a filter (720nm) ISO 160, 1/8th sec, F1.5 With 87 filter (740nm) ISO160. 1/4th, F1.5 That's what I get for not chimping the first set of images. They were Black on the computer, totally different exposure than the one required. The M8- IR was well exposed with the 88a and 87. And now I have a 43mm screw in 87 filter, the Kodak Wratten Gelatin package shows it to be from 1966. Was unopened. The Full-Spectrum Olympus EP2 loses 2 stops with the 88a filter in place. Modern sensors cut back on IR sensitivity compared with those 20 years ago. Link to post Share on other sites More sharing options...
ndevlin Posted February 27, 2015 Share #140 Posted February 27, 2015 Jaap, thanks for the effort, but that file still looks horrendous, except now it's desaturated bad colour. It was this sort of thing that drove me out of the M cameras. Peter P. has spent a tremendous amount of time reaching proficiency is post-processing decent skin tones, first out of the M9 and now the M240. It seems that there is no shortcut. Colour under daylight is great, but mixed-lighting skintones remain a nightmare. Link to post Share on other sites More sharing options...
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