doronski Posted November 19, 2011 Share #1 Posted November 19, 2011 Advertisement (gone after registration) Sorry if this has been covered before. I have included a low res shot to illustrate the problem. Using 50mm summilux f 2.8 at ISO 1250 and I appreciate that the focus is not that great. What is going on over the eye of the girl on the left? I have seen it in one other pic. It is not through my other photos. Any thoughts would be most appreciated. TIA 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/166644-discolouration-advice/?do=findComment&comment=1847801'>More sharing options...
Advertisement Posted November 19, 2011 Posted November 19, 2011 Hi doronski, Take a look here discolouration advice. I'm sure you'll find what you were looking for!
likalar Posted November 19, 2011 Share #2 Posted November 19, 2011 I don't see any problem. Larry Link to post Share on other sites More sharing options...
jaapv Posted November 19, 2011 Share #3 Posted November 19, 2011 Weird light. You've blown a couple of color channels in that highlight. Link to post Share on other sites More sharing options...
jrovner Posted November 19, 2011 Share #4 Posted November 19, 2011 I've seen this also occasionally when photographing in dark venues with colored light, such as stage productions. I'm curious -- if you process this as a black and white image, do the artifacts disappear? That's what I've found. I believe the blown out color channel(s) can be corrected in Photoshop by applying data from a well-exposed channel to the bad channel(s), but because I'm lazy I typically just process in black and white and all is well. Link to post Share on other sites More sharing options...
250swb Posted November 19, 2011 Share #5 Posted November 19, 2011 Really weird. I wonder if the highlights have gone that way on the face due to makeup? Steve Link to post Share on other sites More sharing options...
vonheim Posted November 19, 2011 Share #6 Posted November 19, 2011 Sorry if this has been covered before. I have included a low res shot to illustrate the problem. Using 50mm summilux f 2.8 at ISO 1250 and I appreciate that the focus is not that great. What is going on over the eye of the girl on the left? I have seen it in one other pic. It is not through my other photos. Any thoughts would be most appreciated. TIA If it is the Summilux pre-ASPH you are referring to, I get the same from time to time. It happens when a purple light is nearby. I don't know exactly why the lens does not handle this type of light, but it is more prevalent in low light than bright lit (and I think when the purple is the brightest light in the frame). Lightroom handles it better with default settings than Aperture does. Your picture looks like mine does when viewed in Aperture (blown vs dominant). Attached is one of mine (with a crop of the issue) taken from Aperture. If I remember correctly this particular shot was much better in Lightroom, but not good. If this thread generates an explanation I would be thrilled! Cheers, Knut 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/166644-discolouration-advice/?do=findComment&comment=1848260'>More sharing options...
Dannybuoy Posted November 19, 2011 Share #7 Posted November 19, 2011 Advertisement (gone after registration) That's LED lights for you. I shot some publicity photos for a stage show and the stage lights were ALL LED based and the solarisation effects were pretty full on. Traditional lights with gels don't produce the same effects. Maybe a frequency/wavelength issue? Link to post Share on other sites More sharing options...
doronski Posted November 20, 2011 Author Share #8 Posted November 20, 2011 Thanks for your feedback. It is the modern ASPH lens. I don't think it was the make up, but the angle of light perhaps made some impact. So if it is the LED lights, can anyone make a suggestion as to how to both anticipate it and then prevent it? TIA Link to post Share on other sites More sharing options...
lct Posted November 20, 2011 Share #9 Posted November 20, 2011 Your picture reminds me of files developed in fluorescent mode (so does the castle pic BTW). If you shot it raw, which mode did you develop it in if i may ask? Link to post Share on other sites More sharing options...
doronski Posted November 20, 2011 Author Share #10 Posted November 20, 2011 Ict, Thank you for the question. It was shot in RAW, I am not sure about what you mean in terms of mode of development. The discolouration was evident in the RAW file when I viewed it in Lightroom. Can your elaborate? D Link to post Share on other sites More sharing options...
lct Posted November 20, 2011 Share #11 Posted November 20, 2011 I have no experience with Lightroom sorry but when you develop your file you must have some options like daylight, flash, tungsten and fluorescent i guess. If so, you might wish to try tungsten and compare it to fluorescent for sake of finding the cause of your problem. Link to post Share on other sites More sharing options...
thighslapper Posted November 20, 2011 Share #12 Posted November 20, 2011 Looks like a version of the colour fringing effect you get with extreme contrast margins and blown highlights... aggravated by the aberrations produced at wider apertures ......and the colour balancing adjustment for artificial light has turned it more magenta than usual... I'd look at the colour fringing threads here for an explanation of the optics/physics involved...... Link to post Share on other sites More sharing options...
lct Posted November 20, 2011 Share #13 Posted November 20, 2011 Sure there are blown highlights on the lady's face but this does not explain the magenta cast in the hairs and on the hand though. Link to post Share on other sites More sharing options...
jaapv Posted November 20, 2011 Share #14 Posted November 20, 2011 That is what I meant with weird. There must have been mixed light, possibly with a discontinuous or LED lightsource somwhere. Link to post Share on other sites More sharing options...
Dannybuoy Posted November 20, 2011 Share #15 Posted November 20, 2011 Also have you tried reducing the vibrance in Lightroom? That might sort it a little. Not really sure there's a way to avoid it unless the light source is diffused first. Link to post Share on other sites More sharing options...
wda Posted November 20, 2011 Share #16 Posted November 20, 2011 Sorry if this has been covered before. I have included a low res shot to illustrate the problem. Using 50mm summilux f 2.8 at ISO 1250 and I appreciate that the focus is not that great. What is going on over the eye of the girl on the left? I have seen it in one other pic. It is not through my other photos. Any thoughts would be most appreciated. TIA Doronski, I have spent two minutes in Lightroom, tweaking colours. Given more time and using layer masks in Photoshop, it would be possible to improve the visible hand and arm colour. But you can see that the contamination in the hair has largely gone. I did reset White Balance sampling the white jacket which gave an improved starting point. Given a little more time, I could have improved the skin tones.Remember, also, that my improvements suffer from being made on a compressed JPEG file rather than the original RAW file. Even so, you can see some degree of retrieval is possible. However. pleasing though the result might be, it doesn't answer your question how to avoid it in the future. I suspect that it is caused by uncontrollable colour lighting contamination. Given time and freedom when shooting, I would have set colour balance in camera using my ColorChecker grey card. That would give you a much better starting point for the dominant ambient colour temperature, but I doubt that it would combat those violet/purple lamps. Just accept the unavoidable theatrical effect! 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/166644-discolouration-advice/?do=findComment&comment=1848910'>More sharing options...
adan Posted November 20, 2011 Share #17 Posted November 20, 2011 First, I would say that probably several things are going on at the same time, enhancing and reinforcing one another. 1. The purple areas in general (hand at bottom, hair, face) are all from from the same sources - purple spotlights scattered around the venue. The problem crops up only in the face because it is (a) a lighter color to begin with, and ( a more reflective (shinier) surface that is acting like a mirror at this angle to the light, reflecting the light far more intensely. 2. Blown channels, yes. Likely a "cousin" to the effect I noted here two years ago: http://www.l-camera-forum.com/leica-forum/leica-m9-forum/107297-rainbow-skies.html. When color channels are pushed over the edge, they don't always blow identically, leading to banding in the transition area 3. The saturation (or vibrance) overall seems very high - the lipstick of the girl on the left looks radioactive (!). It is also possible that the camera color calibration settings in Lightroom are not right for this lighting (red saturation set too high and red hue set too magenta). 4. Adjusting white balance for the overall picture can also exaggerate localized effects like this. Knut's example may be showing this too. Bumping up blue to correct for yellow artificial light overall can push blues and purples over the edge. I get a mild version (without the banding) of this if I have a picture shot under greenish fluorescent lights with some daylight in the background - the daylit areas pick up a strong purple cast if I white-balance for the artificial light. It was shot in RAW, I am not sure about what you mean in terms of mode of development. The discolouration was evident in the RAW file when I viewed it in Lightroom. Keep in mind that you never actually "see" a raw file. What you see is always an interpretation of the raw data by means of the settings used in Lightroom (or other programs). There are default settings, but those are not "neutral" or "zero" settings. It is always up to the photographer to decide if the defaults are appropriate for a given picture. As to what to do: 1. Meter carefully in tricky lighting. LED lights may be a factor, but I'll bet this could well have happened also under gelled lights, at this particular glancing angle off the skin. Expose to keep the highlights under control (that is what I did not do in my rainbow-skies examples - I should have metered to make sure the sky was within range, and rescued the shadows in post-processing). 2. Turning DOWN "highlight recovery" in Lightroom may reduce the banding effect. The highlight will still be blown, but the transition area may be smoother. Link to post Share on other sites More sharing options...
akiralx Posted November 21, 2011 Share #18 Posted November 21, 2011 Similar thing here on the left shoulder, although in natural light (bright Aussie sun...). Shot wideopen with Zeiss 50mm C-Sonnar: Link to post Share on other sites More sharing options...
Shade Posted November 21, 2011 Share #19 Posted November 21, 2011 Yes I also get it from time to time, and sometimes I find the shot unsalvageable. The only way was to turn it into a BW shot.. If anyone can share how to avoid it, like others are asking, them I will be very grateful Link to post Share on other sites More sharing options...
mjh Posted November 21, 2011 Share #20 Posted November 21, 2011 Similar thing here on the left shoulder, although in natural light (bright Aussie sun...). That’s a well-known phenomenon that can occur with any of the primary colours. Even when the picture appears to be perfectly exposed on the whole, one of the RGB channels can already show clipping in some areas. Here the red channel suffers from clipping at her left shoulder, resulting in a colour shift towards the second-brightest channel which in this case happens to be blue. Similarly, a bright blue sky can appear cyan due to clipping in the blue channel. In the picture starting this thread there must have been a purple spotlight causing a bright reflection off the skin and a more diffuse reflection off the hair. The reflection off the skin was bright enough to produce clipping in both the red and blue channels, resulting in an unnatural looking colour. Link to post Share on other sites More sharing options...
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