I think after all the threads on this a light is going on in my head.
Those of you having difficulty "filling in" the shadows in your 5D2 files in post could I just ask a question that is bugging me. Do you produce finished work with pure black tones anywhere in your prints? I would have thought that prima facie that would be very desirable (at least it was when I was being trained in the darkroom), but I can't see how you can be doing this apparently routinely pushing shadows in your files by one or more stops.
Perhaps I am misunderstanding your workflow or what you are setting out to achieve.
brainiac wrote:
Uses of the terms underexposure and overexposure on this thread are basically meaningless. Different scenes are of different contrast. Typically a photographer must underexpose darker parts of a scene and overexpose brighter parts. If the contrast in the scene exceeds the DR of the camera, then over and under exposure for the scene as a whole, are not defined. A photographer decides whether to blow highlights, or whether to raze shadows. It is arguable that optimal exposure on a 5D2 is the exposure which retains the very slightest detail in the brightest part of the image, so that after intelligent processing there are no parts of the image where highlight compression occurs due to saturation of the photosites. In order to shoot this way, a landscape photographer would be advised to use the neutral picture style with minimum contrast and saturation so that her histograms and review jpegs show what the sensor is capturing, notwithstanding the gamut limits of the camera's monitor.
The limits of the camera's dynamic range are felt separately in each of the RGB channels. A scene can have enormous contrast in the red channel and almost none in the blue. The same goes for brightness/exposure levels. That is why light temperature can have a dramatic effect on the noise levels found in each separate channel, and why parts of an image that contain brightness in only one primary colour can show much stronger banding than greyer areas. Tungsten bulbs emit much less blue light, so when images are balanced to tungsten it is often the blue channel that becomes noisy and bandy.
Consequently it is pointless to regard 'fill light' type processing as excessive. It is just another way of maximising the camera's capabilities. Some people like large areas of blackness in their images. Other prefer not to use a camera as if it's a photocopier. I have seen banding on 5D2 shots which were exposed to preserve highlights, and then processed to maximise dynamic range by setting contrast to minimum, i.e. opening up the shadows. The visibility of banding is certainly affected by how much detail lies in the shadow areas of the image, how deep the shadows are in brightness (i.e. how far they are in exposure from the brightest parts of the image, assuming the highlights are not blown), and colour balance.
The problem with the 5D2 is that it has large scale banding in its noise footprint which is clearly visible at web image sizes. This kind of banding noise is virtually impossible to fix and it means that shadows can not be retrieved as successfully as they could be if it weren't there. Canon has clearly tackled this limitation in subsequent cameras, namely 500D, 7D and 1D4, so we can expect the 5D3 to have much less banding, and probably be a much better camera for coping with high contrasts scenes. Due to 5D2's banding, and the fact that it has been fixed in subsequent Canon cameras, we can also expect the 1D4 to exceed 5D2 in dynamic range and credible tone. It will be a great shame if those who don't like 1 series cameras are made to wait 2 more years for a light full-frame camera that lacks this flaw.
So what does it take? I have seen banding at 100 iso in an azure sky that was a stop underexposed. I have seen it in shadows of a street scene at iso 100 when the sky was only just not blown. It's all over the place, but in most cases it is slight and only subtly undermines the sense of reality in the image. I wonder if the horizontal line in the crop of the woodland scene at the top of this thread is banding. I think it's a feature of 5D2 files at all isos whenever you use low contrast settings in order to cope with high contrast scenes. The effect is usually subtle but it's often there. It might take a trained eye to spot it, but it only takes an average eye to be subliminally effected by it....Show more →
By the sounds of it, my 5D2 will be long gone before I truely understand all of that
AdrianRogers wrote:
By the sounds of it, my 5D2 will be long gone before I truely understand all of that
It's basically a summary from what we have been discussing/presenting in this thread, with some corrections and additions... Brainiac certainly has a way with words
brainiac wrote:
It's all over the place, but in most cases it is slight and only subtly undermines the sense of reality in the image. I wonder if the horizontal line in the crop of the woodland scene at the top of this thread is banding. I think it's a feature of 5D2 files at all isos whenever you use low contrast settings in order to cope with high contrast scenes. The effect is usually subtle but it's often there. It might take a trained eye to spot it, but it only takes an average eye to be subliminally effected by it.
Although here we seem to differ from opinion. First, I don't see a horizontal line in the woodland scene. Secondly, I don't see banding in every image.
The problem with the 5D2 is that it has large scale banding in its noise footprint which is clearly visible at web image sizes. This kind of banding noise is virtually impossible to fix and it means that shadows can not be retrieved as successfully as they could be if it weren't there. Canon has clearly tackled this limitation in subsequent cameras, namely 500D, 7D and 1D4, so we can expect the 5D3 to have much less banding, and probably be a much better camera for coping with high contrasts scenes. Due to 5D2's banding, and the fact that it has been fixed in subsequent Canon cameras, we can also expect the 1D4 to exceed 5D2 in dynamic range and credible tone. It will be a great shame if those who don't like 1 series cameras are made to wait 2 more years for a light full-frame camera that lacks this flaw.
This certainly sounds like something that should be repairable in firmware.
In my experience problems which appear random usually aren't, but rather have complex dependencies. It seems to me (as a non-owner of a 5DII) that you need to approach the problem systematically. Find a situation which demonstrates the problem, then systematically change everything on the camera (metering mode, AF mode, ISO, noise reduction, everything..) and see what happens. Maybe even look at seeming unrelated things like CF card type, proximity of mobile phones, overhead power cables etc. If that lot yields no results, you can assume that the RF interference is not to blame and start looking at elements of the picture (colour hue, clipped colour channels, type of lighting, etc). Perhaps temperature is a contributing factor too.
Alternatively hunt through images which show the problem and try to find similarities - a sort of data mining exercise.
Given how long this has been a topic of discussion, and the fact that Brainiac has been looking at it a fair bit, i can't help feeling that anything less than a completely rigorous (and time-consuming) approach will give the answer. Think of it like playing CSI, but with real scientific method
15Bit wrote:
Given how long this has been a topic of discussion, and the fact that Brainiac has been looking at it a fair bit, i can't help feeling that anything less than a completely rigorous (and time-consuming) approach will give the answer. Think of it like playing CSI, but with real scientific method
15Bit wrote:
i can't help feeling that anything less than a completely rigorous (and time-consuming) approach will give the answer. Think of it like playing CSI, but with real scientific method
Yeah... unfortunately I don't have that time available. So, in the meantime... exposing to the right and hope for the best
Brainiac: Would this test demonstrate anything usefull at all..? Regarding what you said about varying dynamic range in each of the R G and B channels, If i were to set up a studio portrait exceeding the dynamic range of the camera (but with plenty of variation in the middle of course), but one blasted with blue light, green light and red light? (Just using gels on flash). I'm certainly not about to pretend I know anything more about this than the usual ramblings, so I won't bother trying if it won't even theoretically show anything worthwhile.
If you can think of any alterations to that test, or something similar (perferably not something too time consuming) i'de be happy to try it.
AdrianRogers wrote:
Brainiac: Would this test demonstrate anything usefull at all..? Regarding what you said about varying dynamic range in each of the R G and B channels, If i were to set up a studio portrait exceeding the dynamic range of the camera (but with plenty of variation in the middle of course), but one blasted with blue light, green light and red light? (Just using gels on flash). I'm certainly not about to pretend I know anything more about this than the usual ramblings, so I won't bother trying if it won't even theoretically show anything worthwhile.
If you can think of any alterations to that test, or something similar (perferably not something too time consuming) i'de be happy to try it....Show more →
That's a generous offer and shows the spirit that keeps many of us coming back here, with thanks. Personally I have seen enough of my 5D2's performance to know it pretty well, and I'm not sure what such a test would add. I don't think this is an intermittent problem, as it consistently limits my use of the camera. All cameras have limits, and this one is only very very slightly tighter than some other Canon cameras. Clearly it doesn't bother some people at all, so I think the best advice to anyone thinking of getting a 5D2 for general use is: get it, it's a brilliant camera, and if this turns out to be an issue for you, sell it and move on. I continue using mine despite this limitation. I very rarely shoot at 100 iso though, so the low light high iso performance is more important to me.
However, I do notice the lack of this kind of banding in 500D and 7D files, and it's frustrating to be able to see how good the 5D2 would be if it had the same sensor electronics as those cheaper cameras. I just hope we don't have to wait too long for a less noisy lightweight full frame Canon, as the 7D is already giving the 5D2 a run for it's money in terms of usability of high isos with low banding.
The problem is the lack of randomness in the noise floor. All circumstances in which that noise floor becomes apparent, produce the burlap effect in my experience.
BTW, I think it's quite easy to demonstrate the burlap noise reliably. Shoot a scene which has a fairly wide range of exposure values, where there is information in the shadows, and flat shadow areas. Set the contrast to minimum in DPP, export to photoshop, and run auto-levels. The burlap will become clearer if you have raised the brightness by a stop or two in DPP. Eccentric colour balances and lower light will make it worse. The pattern seems to be a feature of the sensor reading electronics.
I received my 5DII last week--a very recent build. I still have time for return or exchange so I've been trying to reproduce the shadow banding problem. Maybe the newer cameras off the line have had the problem minimized?
In any shots I would ever consider to be keepers I have no banding issues. I can find it deep down at ISO 100 if I shoot a black object in low light, but it doesn't show until I lift the black objects (Shadows/highlights) in CS4 30-40% (way beyond my workflow). With "normal" underexposed shadows I can't find any major fault.
I got horrible banding problem with my iso 100 shots. I usually expose to the right. Processed the image with a bit contrast and red or orange like filters to convert to black and white.
Semorg, firstly lovely processing! I've found with processing pictures to B&W for deep black skies that you get quite a lot of artifacting/posterisation when doing so, an 8 bit file will fall apart immediately, 16 bit files can take more punishment but noise becomes exaggerated, etc.
That said there is no excuse for the banding in those mid tones. Ouch.
Just got back from 2 days of shooting in the ancient kabbalistic town of Safed (commercial gig and I stayed over for a 2nd day). When you have moving elements forget bracketing. When you're stitching, forget bracketing. When you have a complex scene forget bracketing. When you have all 3 and about 5-7 stops between the shadows and highlights, bracketing is just a post processing nightmare. Combine all of the above and you pretty much get what I've been shooting for a couple of days. The only way to hold highlights and keep details in the shadows without pushing them is to use huge lighting rigs and that doesn't really work for landscape/street work exactly. You can shoot at certain times of the day, approximately 1.5 hours per day of diffused light but then you don't have the shutter speed to work with the aperture/DOF/perspective/foliage or people freezing, etc.
So you sacrifice, the sacrifice is far better than it was in the provia/velvia days. Far less do we have to pick the shot to suit the medium, a way of thinking that I hate as hugely limiting expression. That said, I'm very wary of a camera that will have less ability to 'get the shot in one' with a high DR scene than my 5D's. If it's a tossup between megapixels and DR, I'll take DR any time when I already have the sharp 13 megapixels of the 5D, I stitch when I need bigger and to be honest, it's only us photographers who give a flying f*** about the huge sharpness and detail once you get past a certain level. Was in an art gallery last week, saw a badly printed, very soft and even blurred 8X10" print sell for $1500. I can't make those prices with my sharp big prints so who is more correct? The megapixel hunter or the artist?
I'll post pics showing where I need all the shadow pushability I can get and no 'expose perfectly' would have helped - when I get a second to do processing. Just got some album orders in and it's the wedding stuff that pays the bills, my other stuff is just project work.
I can understand your disappointment, your images are really beautiful except for the banding. I've got a recent 5D2 file with a strong blue sky and I would like to process that image in a similar way to your images to see if I can replicate the issue. Can you advise a little more literally what your processing involved please?
I find when I push the shadows using Exposure Compensation and Fill Light, the noise and banding get vicious.
HOWEVER - pushing the exposure just as far (or further), then bumping the Black Level down to 0 from 5 will boost the shadows considerably, and does not add NEAR the horrendous shadow noise of the "fill light" method. Further tweaking can of course be done, but I must say that I am significantly happier with both the amount and the grain of the noise using this method.
I'd encourage others to try this method using the "create virtual copy" feature and compare the "Black Level" change versus the "Fill Light" change on your images.
Fat Dave wrote:
HOWEVER - pushing the exposure just as far (or further), then bumping the Black Level down to 0 from 5 will boost the shadows considerably, and does not add NEAR the horrendous shadow noise of the "fill light" method.
I agree, moving the blacks slider back opens up the shadows in a more mildly fashion. In general, it seems the 5D2 are a lot more contrasty to begin with than files from other cams I have used.
Note that semorg is struggling to retain information in a very high contrast scene. These are precisely the conditions in which my 5D2's trash tone.
We have seen enough examples in this forum from different raw convertors that I think it's fair to say that it's the camera, not the processor. But the processing requirements that expose this problem aren't familiar to everyone, which explains why we get so many spoilers who claim the problem is imaginary. Those people just probably never use low contrast to preserve dynamic range and retain tones in deep shadows. They typically advocate crushing dark shadows to black as a solution, although it's only a partial one and makes your pictures look cruder in tone.
Let's keep this in perspective though: it's a very minor limitation to what is otherwise a great camera. Only those who like to push the limits and retain tone across a wide range of exposure values will come across it.
