maddav Posted September 12, 2009 Share #1 Posted September 12, 2009 Advertisement (gone after registration) Hello, I am trying to determine if the banding I see is normal or if my sensor is a bad one. I have sent samples to Leica, they would like to see the files but I need my camera and the only way to get it back quickly if I sehip it to Solms is to pay €100 for the fast service. If this banding issue is unfortunately normal I don't feel like wasting €100... Attached is one picture that shows the problem, particularly on the boys's chest. The image is underexposed so you will see it best if you push the levels with photoshop... That may unfortunately be 'normal' noise for this camera. Note also that the picture is saved in Adobe98 so it is best viewed with a software that can handle color profiles. 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/96467-leica-m8-and-banding-at-iso-640/?do=findComment&comment=1031059'>More sharing options...
Advertisement Posted September 12, 2009 Posted September 12, 2009 Hi maddav, Take a look here Leica M8 and banding at ISO 640. I'm sure you'll find what you were looking for!
mboerma Posted September 12, 2009 Share #2 Posted September 12, 2009 I don't see anything wrong. It's just because it is underexposed by 2 or 3 stops and this causes the banding when trying to rescue the shadow areas. Link to post Share on other sites More sharing options...
okram Posted September 12, 2009 Share #3 Posted September 12, 2009 I am afraid that it seems (from what you show) like a malfunction. I have never seen any banding on my 640 and similar at 1250 (dont use it much). Try to take ISO 160 (darker and even lit picture) and move the exposure/fill light few stops, - it will probably reveal such banding- and there should be none at given ISO. At least I have none. Link to post Share on other sites More sharing options...
maddav Posted September 12, 2009 Author Share #4 Posted September 12, 2009 I don't see anything wrong. It's just because it is underexposed by 2 or 3 stops and this causes the banding when trying to rescue the shadow areas. It is underexposed by ca. 1 stop which is not very much... certainly not 2 or 3. The banding becomes very annoying if you push the exposure by +0.8 in the raw file. But then again what is the purpose of shooting digital if you cannot do a +0.8 correction? @Okram: no it doesn't seem to show at lower ISOs even if I push the exposure at +3... Link to post Share on other sites More sharing options...
farnz Posted September 12, 2009 Share #5 Posted September 12, 2009 I see the banding you're talking about and it seems to extend at least across to the woman's chest as well. I suspect that it may be caused by the overexposed area at the right of the picture around the man's elbow, which is at the same height. I have seen similar banding in my photos but I've always been able to trace the cause to a heavily overexposed area at the edge of the frame. My guess is that in your picture the black 'reference' pixels that sit just outside the frame are being affected by saturated pixels at the edge of the frame. It may be that there is just too much dynamic range in the picture for the M8's sensor to cope with at ISO 640. Pete. Link to post Share on other sites More sharing options...
Jamie Roberts Posted September 12, 2009 Share #6 Posted September 12, 2009 It is underexposed by ca. 1 stop which is not very much... certainly not 2 or 3.The banding becomes very annoying if you push the exposure by +0.8 in the raw file. But then again what is the purpose of shooting digital if you cannot do a +0.8 correction? @Okram: no it doesn't seem to show at lower ISOs even if I push the exposure at +3... No, it's underexposed by 2 or 3 stops for the subjects, sorry. There's virtually no important information in the file above RGB 128/128/128... so it's a tosser, not a keeper... sorry. The girl's face kicks in at RGB 60/60/60...the shadows. It should be hitting 230/230/230 in the highlights. IOW, this photo is a mess. But you knew that by looking at it right? But having said that, there's three important lessons here: 1) if you see the banding then your monitor is truly messed up, and working at ridiculously high levels for print, unless of course, your prints are illuminated by klieg lights at 2 feet. 2) When you do a levels to see the "banding" you're seeing the sensor being asked to operate not at ISO 640 but more like ISO 5000 or 10000. It will not do that. The "banding" then results from the highlights at the right and run across the sensor, but it's hardly a camera flaw. Again, you're not pushing +.8 or something... more like +3 EV for the boy. 3) The OP need to understand exposure a bit better before complaining about the camera. Seriously; if you had exposed this by 2 more stops you'd have a shot here. Expose for the subject and try to control the highlights. So you have 2 options here... and only two: blow the highlights and add (at least) 2 stops OR add 2 stops of light to the subject. It's not the M8. Link to post Share on other sites More sharing options...
maddav Posted September 12, 2009 Author Share #7 Posted September 12, 2009 Advertisement (gone after registration) Sorry I see the banding and I have just calibrated my monitor. That said I agree it is not obvious until I push it to +0.7/+0.8. While I agree the picture is underexposed, I simply wouldn't like to have it exposed 2 or 3 stops higher: it would ruin the mood... What is the correct exposure? I don't need to look at RGB values to tell if I LIKE the exposure or not. The point is there will always be dark areas in a photograph and I don't want to see banding in them... It is my business if I want to have the subject in a dark area or in a bright one. If the main subject was located in the highlights, we would still see the banding in the shadows and that's the problem... Link to post Share on other sites More sharing options...
Jamie Roberts Posted September 13, 2009 Share #8 Posted September 13, 2009 Sorry I see the banding and I have just calibrated my monitor. That said I agree it is not obvious until I push it to +0.7/+0.8. While I agree the picture is underexposed, I simply wouldn't like to have it exposed 2 or 3 stops higher: it would ruin the mood...What is the correct exposure? I don't need to look at RGB values to tell if I LIKE the exposure or not. The point is there will always be dark areas in a photograph and I don't want to see banding in them... It is my business if I want to have the subject in a dark area or in a bright one. If the main subject was located in the highlights, we would still see the banding in the shadows and that's the problem... Ok I'll bite (but I know I shouldn't). What illumination do you have your monitor calibrated to? What kind of monitor is it again? You're complaining about banding that's invisible at normal viewing illumination. About RGB values that are so dark they'd get compressed to nearly nothing by printing. And you don't need to know RGB values unless you want to understand what the sensor saw. In this case, almost nothing except the little bit of light on the girl's face.. And sure--it's your choice if you want to keep the boy in silhouette. I assumed when you said there's banding there you meant he was the subject and something important. For next time, if you want to make sure there's no banding there, and you want to keep it dark, then understand how a digital camera works and do what I said: expose more stops so you have detail (or add light) underdevelop in post so you have the mood you want clip unimportant shadows Look, we did the same on film. What you've done here is make the equivalent of a nearly clear neg in the shadow. It's "thin" in every place of interest. The exposure is off. Unfortunately, unlike film, many digital sensors (and certainly the m8's) band when you ask them to record stuff at ISO 10000. Of course, you could just sink the values below the girl (from RGB 000 to 60 60 60--in this case around RGB 17 17 17) and voila! Problem solved, and contrast added. You can even bring the midtones in the face up and get more mood and a better print. So I stand by what I said. If you don't want to see banding on a shot like this, then expose more and correct. But don't expect to "dodge and burn" without recording any detail. I'm not trying to be harsh here either, sorry if it comes across that way. But you simply didn't expose far enough to record what you needed without getting a ton of (perfectly normal at sensor limits) artifacts. BTW--Pete (Farnz) is probably right as well.. the overexposed peice on the right probably isn't making things easy for the sensor (or RAW processor) either. Just to show you what a levels correction does (with shadows clipped at 20 20 20)--is this the kind of thing you were looking for? You shouldn't see any banding here: 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/96467-leica-m8-and-banding-at-iso-640/?do=findComment&comment=1031989'>More sharing options...
mboerma Posted September 13, 2009 Share #9 Posted September 13, 2009 Could have said it any better, Jamie. (man, you're an eloquent writer.) Link to post Share on other sites More sharing options...
maddav Posted September 13, 2009 Author Share #10 Posted September 13, 2009 No I don't see any banding on your attachment. But the contrast is way too harsch: that's definitely not what I would like to have. The point is I start seeing banding on this picture when I push the exposure in the raw file by 1 stop... That doesn't seem so much too me. That's why I don't understand your statement that: "Unfortunately, unlike film, many digital sensors (and certainly the m8's) band when you ask them to record stuff at ISO 10000." This picture was recorded at 640 and if I increase the exposure by +1 I'm "asking the sensor to record stuff at 1280". That's not 10000. Iso 10000 is 4 stops higher and I would certainly not complain if I saw banding when increasing by +4. Link to post Share on other sites More sharing options...
mboerma Posted September 13, 2009 Share #11 Posted September 13, 2009 No I don't see any banding on your attachment. But the contrast is way too harsch: that's definitely not what I would like to have. The point is I start seeing banding on this picture when I push the exposure in the raw file by 1 stop... That doesn't seem so much too me. That's why I don't understand your statement that: "Unfortunately, unlike film, many digital sensors (and certainly the m8's) band when you ask them to record stuff at ISO 10000." This picture was recorded at 640 and if I increase the exposure by +1 I'm "asking the sensor to record stuff at 1280". That's not 10000. Iso 10000 is 4 stops higher and I would certainly not complain if I saw banding when increasing by +4. Can you give me a link to the original DNG? What Jamie is trying to tell you is that is the RAW file is not containing the information, because it was technically underexposed by a couple of stops, to increase the exposure with 1 then it is not possible to do it without the banding or other artifacts showing up. Link to post Share on other sites More sharing options...
okram Posted September 13, 2009 Share #12 Posted September 13, 2009 Jamie, this is banding on both: (I dont have such on my camera) 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/96467-leica-m8-and-banding-at-iso-640/?do=findComment&comment=1032465'>More sharing options...
graeme_hutton Posted September 13, 2009 Share #13 Posted September 13, 2009 I've experienced this but between very similar exposures - One banded, others in the series not, which I find difficult to explain: 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/96467-leica-m8-and-banding-at-iso-640/?do=findComment&comment=1032483'>More sharing options...
RobertW Posted September 13, 2009 Share #14 Posted September 13, 2009 Banding issues aside, this is just a severely underexposed picture. You need to overexpose... Jamie's advice works well: Meter on the dark portions of the subject you want to see, which effectively overexposes by 1 or 2 stops Underexpose in PP to bring back the shadows/ambiance that you like Your bands should disappear following his advice. Best Rob Link to post Share on other sites More sharing options...
farnz Posted September 13, 2009 Share #15 Posted September 13, 2009 Maddav, Here's a curve ball for you prompted by Greame Hutton's pictures: the banding *could* be caused by electromagnetic interference from a source close by. For example many people keep their mobile phone in their top pocket, which is close to the M8 when shooting, and mobile phones are continually going through a 'handshake' with the nearest base station where the base station sends out a signal to ask "I have you registered on my cell are you still there?" to which the mobile phone will reply "Yes". The phone's answer in particular will cause a strong electromagnetic field to be set up and varied as the phone as the phone transmits its message to the base station. If the camera's close enough and not effectively shielded then the electromagnetic field will be able to induce voltage into its circuitry (because the wires and circuit board tracks will act like tiny aerials at 1800 GHz). If the phone is replying to a handshake, which will be invisible to the photographer, at the same moment as the camera's sensor is processing a photo or writing to an SD card then the camera's signal could be affected by the phone's transmission. The banding in the pictures consists of evenly-spread bands, which fits with a digital (carrier) transmission that I'd expect from a phone. (Incidentally, if the sensor's line frequency was known it would be possible to calculate the frequency of the interference by measuring the uniform distance between the bands.) All electronic equipment has to conform to a variety of FCC, IEC, BS, DIN etc regulations on electromagnetic emissions and immunity but there are many cases where evidence of compliance is spurious at best and rare incidences where compliance is not possible. I could be way off track here but there is a certain plausibility. Pete. Link to post Share on other sites More sharing options...
Nicoleica Posted September 13, 2009 Share #16 Posted September 13, 2009 Following on from Pete's post above. I'm sure that most of you are aware that when traveling by air, your memory cards are best left in your bag, rather than your pocket. X-rays don't affect cards in the same way that they do films, but some metal detector scanners can nuke a card without blinking. Likewise, try to avoid leaving memory cards in close proximity to a CRT screen (TV or computer monitor.), as some can generate a hefty RF & magnetic field. Link to post Share on other sites More sharing options...
graeme_hutton Posted September 13, 2009 Share #17 Posted September 13, 2009 Interesting theories. My shots were on 'multi-exposure' setting, so in very quick succession and probably identical exposures. I don't believe they are 'severely underexposed' Rob, besides as I mentioned, only one frame shows banding the shots immediately before and after have none. Best Graeme Link to post Share on other sites More sharing options...
maddav Posted September 13, 2009 Author Share #18 Posted September 13, 2009 Graeme, this is very interesting because it shows that this banding is really a problem of the camera (whether it depends on particular cameras or is a flaw common to all M8s - I would assume the former) and not just noise brought by underexposure (although for sure there is a strong correlation between underexposure and banding)... Your shot is not underexposed. As for the cell phone theory, most of the time I didn't have my phone with me and if I had it it was in my trousers' pocket, not in my shirt pocket... I think unfortunately the M8 doesn't need a phone to 'band'. Link to post Share on other sites More sharing options...
maddav Posted September 13, 2009 Author Share #19 Posted September 13, 2009 Graeme, If that is not too indiscrete, may I ask you the serial number of your M8? Mine is an early one, it was bought in December 2006. Link to post Share on other sites More sharing options...
graeme_hutton Posted September 13, 2009 Share #20 Posted September 13, 2009 Graeme,If that is not too indiscrete, may I ask you the serial number of your M8? Mine is an early one, it was bought in December 2006. It's only once this has happened I think and I'm certainly not Leica bashing...You would have to prize my M8 from my cold dead hands! (or give me an M9!). S/N begins 3200 bought Dec 07. Graeme Link to post Share on other sites More sharing options...
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