acanalda Posted November 7, 2009 Share #1 Posted November 7, 2009 Advertisement (gone after registration) Hi to all Following I enclose some photos. The first one surprised me because the colors, specially the "blue" shirt (the real color is magenta). ISO 160, WB Auto, Summilux 1:50 at 1,4 with leica UV/IR filter. Lens detection On+UV/IR The second one. In this case the shirt has the correct magenta color. ISO 160, WB Daylight, Summilux 1:50 at 1,4 WITHOUT IR/IV filter. The third one. same that the second but with WB set to auto. In this case again, the colors are wrong. What do you think ??? Regards, Arturo 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/102863-what-happens-with-my-m8-wb/?do=findComment&comment=1106674'>More sharing options...
Advertisement Posted November 7, 2009 Posted November 7, 2009 Hi acanalda, Take a look here What happens with my M8 WB ????. I'm sure you'll find what you were looking for!
epand56 Posted November 7, 2009 Share #2 Posted November 7, 2009 Happens to me as well sometime, same picture and settings, total different colours. I suppose it depends on the UV/IR filter interaction with the sensor, but I'm not really able to explain that. Though what surprise me, is that when happens, I'm generally using the 50 Lux asph. Link to post Share on other sites More sharing options...
dpattinson Posted November 7, 2009 Share #3 Posted November 7, 2009 If as you say - the colours in the second shot are correct. Then it seems likely that the AWB has tried to neutralize what it saw as a warm colour cast. Almost all of the frame is full of warm tones, and I expect the AWB thought it best to attempt to make the overall balance neutral. Link to post Share on other sites More sharing options...
lct Posted November 7, 2009 Share #4 Posted November 7, 2009 Is the pencil case black? If so you've got some strong blue cast in pics 1 and 3. I would avoid auto WB personally. Link to post Share on other sites More sharing options...
mjh Posted November 7, 2009 Share #5 Posted November 7, 2009 In the second image, the histograms of the red, green, and blue channels look rather uneven, red being quite dominant which is indicative of a low color temperature. The AWB apparently tries to correct for that. Also the lighting of the front and background seems to differ with a higher color temperature in the foreground than in the background. Link to post Share on other sites More sharing options...
pthompson Posted November 7, 2009 Share #6 Posted November 7, 2009 Do you have an upgraded firmware version? I don't recall the numbers, but WB function in earlier versions was not very subtle, to say the least. The difference shown in your examples reminds me of my early days with the M8... Link to post Share on other sites More sharing options...
SJP Posted November 7, 2009 Share #7 Posted November 7, 2009 Advertisement (gone after registration) Unless you shoot jpegs out of the camera the WB is totally irrelevant as the DNGs contain the image "as it is". When importing into C1 or whatever the WB settings (auto, daylight, tungsten etc.) will be imported as the base setting for the WB correction. So for all three images above the DNG files have captured the same light, they are just rendered differently. In post procesing select the image you like in terms of white balance and then copy/paste the WB settings to the others - this takes about 2 seconds and you are done for the whole set. Despite numerous protests for me the original auto WB which only had 4 or 5 presets (daylight, tungsten, fluorescent etc.) made more sense from a photographic point of view. Auto WB throws the natural light quality out of the window and replaces it by average blandness which is nearly always wrong unless I happen to be taking a picture of a gray building at noon. Nevertheless I still use it and then postprocess afterwards as it gives me a starting point that can be useful as a rough indication of what might work. Link to post Share on other sites More sharing options...
lct Posted November 7, 2009 Share #8 Posted November 7, 2009 Guessing that the pencil case is black there is indeed a strong blue cast in pics 1 and 3 as suggested above. Sounds like the culprit is auto WB as often. Better use manual WB or shoot raw IMO. Pic 1 + 1 click on the pencil case in iCorrect: 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/102863-what-happens-with-my-m8-wb/?do=findComment&comment=1107062'>More sharing options...
acanalda Posted November 7, 2009 Author Share #9 Posted November 7, 2009 Guys, I only shoot DNG ! That's why I can't understand what happens and why the WB has this effect. Regards Arturo Link to post Share on other sites More sharing options...
mjh Posted November 7, 2009 Share #10 Posted November 7, 2009 That's why I can't understand what happens and why the WB has this effect. I’m not sure why it matters so much when you shoot DNG anyway, but any AWB has to take guesses – TTL white balancing isn’t an exact science. As I had mentioned above, Leica’s AWB might partly rely on an analysis of the RGB histogram which would explain your results. Link to post Share on other sites More sharing options...
lct Posted November 7, 2009 Share #11 Posted November 7, 2009 ...I only shoot DNG !... Sounds like you did not choose the right settings in your raw converter then. What converter did you use? Link to post Share on other sites More sharing options...
acanalda Posted November 7, 2009 Author Share #12 Posted November 7, 2009 Sounds like you did not choose the right settings in your raw converter then. What converter did you use? Ict, I use Mac Aperture 2.1.4 Regards, Arturo Link to post Share on other sites More sharing options...
lct Posted November 7, 2009 Share #13 Posted November 7, 2009 ...I use Mac Aperture 2.1.4... Ah sorry i don't have it. Did you watch this video? How to adjust white balance in Aperture | Other Applications Video « Wonder How To Link to post Share on other sites More sharing options...
ho_co Posted November 8, 2009 Share #14 Posted November 8, 2009 Arturo-- Trying to put the two suggestions together: The DNG is tagged with what the camera thought was the best WB for the shot. Once you're in your image processor, you can compensate non-destructively to your heart's content, using the girl's collar or the pencil case to set white balance. In other words, yes, the camera read the white balance differently for the three shots; but it can be adjusted in post-processing. But that's all beside the point; what you're asking is, "Why does this happen?" Were these images shot in "Continuous" mode? For some reason that I've never seen explained, the M8 seems sometimes to have more problem settling on AWB when making repetitive images of the same scene. You'll notice also that pictures 1 and 3 cover approximately the same frame, but picture 2 is framed differently. Therefore, something in images 1 and 3 may be confusing the WB, or something in picture 2 correcting it. You are using the M8's required UV/IR-Cut filter, aren't you? Michael's explanation, coupled with the reframing, is probably the most reasonable. pthom's suggestion is a good one: Be sure you're using the latest firmware. But my guess is that you're doing that, or your results would be more inconsistent than these. Best practice for a situation like this is to use a WhiBal card (for example) or to set WB manually, possibly with an ExpoDisc. Second best practice is to correct in Aperture. Link to post Share on other sites More sharing options...
acanalda Posted November 8, 2009 Author Share #15 Posted November 8, 2009 Ah sorry i don't have it. Did you watch this video?How to adjust white balance in Aperture | Other Applications Video « Wonder How To Thanks Ict I have seen the video. This solves the problem but I am interested in origin. What causes this strange effect ?. regards, Arturo Link to post Share on other sites More sharing options...
lct Posted November 8, 2009 Share #16 Posted November 8, 2009 Hi Arturo. Just poor auto WB to me but i'm no techie at all. Link to post Share on other sites More sharing options...
acanalda Posted November 8, 2009 Author Share #17 Posted November 8, 2009 Arturo--Trying to put the two suggestions together: The DNG is tagged with what the camera thought was the best WB for the shot. Once you're in your image processor, you can compensate non-destructively to your heart's content, using the girl's collar or the pencil case to set white balance. In other words, yes, the camera read the white balance differently for the three shots; but it can be adjusted in post-processing. But that's all beside the point; what you're asking is, "Why does this happen?" Were these images shot in "Continuous" mode? For some reason that I've never seen explained, the M8 seems sometimes to have more problem settling on AWB when making repetitive images of the same scene. You'll notice also that pictures 1 and 3 cover approximately the same frame, but picture 2 is framed differently. Therefore, something in images 1 and 3 may be confusing the WB, or something in picture 2 correcting it. You are using the M8's required UV/IR-Cut filter, aren't you? Michael's explanation, coupled with the reframing, is probably the most reasonable. pthom's suggestion is a good one: Be sure you're using the latest firmware. But my guess is that you're doing that, or your results would be more inconsistent than these. Best practice for a situation like this is to use a WhiBal card (for example) or to set WB manually, possibly with an ExpoDisc. Second best practice is to correct in Aperture. Thanks Howard. No, the images weren't shot in continous mode. I took the first one and when I checked it in the camera screen I noticed the strange color. Then I removed the IR/UV filter and I took the second photo. In this case the colours are ok. For the third photo I have changed the WB setting and, again, the colours went wrong. Why my 200 euro canon Ixus works fine in this conditions and my Leica don't ? Regards, Arturo Link to post Share on other sites More sharing options...
mjh Posted November 8, 2009 Share #18 Posted November 8, 2009 I took the first one and when I checked it in the camera screen I noticed the strange color. Then I removed the IR/UV filter and I took the second photo. In this case the colours are ok. For the third photo I have changed the WB setting and, again, the colours went wrong. This is slightly at odds with what you wrote in your first post, namely that the first and third images were taken with AWB and the second with daylight WB. That you took off the IR/UV filter for the second shot will probably not have made that much off a difference (although it is generally better to leave it on). There is nothing suprising here really. The daylight preset you used for the second shot preserved the effect of particular lighting of that scene – it is a bit too yellow-reddish for my liking, but of course that’s a matter of preference. In the the first and third shot, the automatic white balance tried to correct for the perceived reddish tint (which is obvious from the RGB histogram), resulting the blueish skin tones. Why my 200 euro canon Ixus works fine in this conditions and my Leica don't ? Can you show us a comparison shot of the same scene taken with the Ixus? Different vendors use different AWB algorithms and a Canon camera will behave differently from a Leica; still it will go wrong under certain conditions – any kind of TTL AWB will, just under different conditions. In this case, a camera with face detection might yield better results, provided it can detect the face in profile. Link to post Share on other sites More sharing options...
ho_co Posted November 9, 2009 Share #19 Posted November 9, 2009 Why my 200 euro canon Ixus works fine in this conditions and my Leica don't ? Arturo, thanks for responding to my conjectures! I've had little problem with my M8's AWB since installing the firmware in which Leica completely rewrote the AWB algorithms. But that said, I think the M series expects a bit better knowledge of exposure, white balance, dynamics etc than is required of a point-n-shoot camera. Often enough, I get a good picture with my D-Lux 4 that I would never have got with my M8, simply because it would take me longer to get to the M8, focus, and shoot (on Automatic, all the while hoping I had left my lens at a good aperture for the exposure). But I've watched other M-shooters raise, focus, shoot in less time than it takes me to get the D-Lux 4 ready. That's due to my own lack of experience and comfort with the M8. The D-Lux 4 gets more use because it is always with me, except when I pick up the M8 to "go do something serious." I can't say why some of your results are as they are, but several folks here have mentioned likely reasons. Your Ixus is built to give good-enough results in most situations. The M8 is built to give excellent results in all situations when properly set. That's not putting down any practice or any camera. Cameras are different, and some require more knowledge or more practice than others. I, for one, am still learning. Link to post Share on other sites More sharing options...
Fotomiguel Posted November 9, 2009 Share #20 Posted November 9, 2009 WB with CS4. For me is always necessary for the final touch! 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/102863-what-happens-with-my-m8-wb/?do=findComment&comment=1109009'>More sharing options...
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