[quote name='Pinhole' timestamp='1287611520' post='3711']
Very informative post, thanks, Wim!
All discussions of resolution aside, I feel that with a Canon 5D MK II I am at a level that is perfectly adequate (prints above A2 are very rarely called for) - but what I really want is more dynamic range. Maybe I'm wrong here, but I feel that the industry is selling their new technology on the strength of megapixels because it's easier than improving dynamic range.
[/quote]
Thank you, Pinhole, it's a pleasure.
To a degree you're right. There are also several aspects to this. Sensor DR really is already better than film, at least in RAW files, namely approximately 10 stops, and if you push it you can get to about 12.
In order to get more out of a sensor, we actually need better AD and related circuitry. Current sensors, especially FF ones, are already capable of approximately 15-16 stops of DR, but making a good AD converter at a reasonable price that can handle this, especially at the noise levels required, is still a long way out of scope. I have been told there actually are cameras out there than can do approximately 16 real stops of DR, but those are rather expensive, and only made to order. Eventually, the technology will permeate down to general use, just like we see and have seen with, e.g., car improvements like disc brakes. I do think this still is some time off however.
A second thing to note is that in print, due to th elimited DR possible as paper can only be so reflective and inks only so black, you lose a lot of this DR, and in order to make prints that look right, you somehow need to compress the DR into a smaller space, in a way similar to what we used the Zone System in the past for. And even on screen this is true. Thsi does fool th ehuman eye and brain to think we actually see what was there in the original scene BTW.
I would therefore suggest that if you feel you are lacking in this area, to pick up some reading on the Zone System. There even are books on how to apply this with digital, and take it from there. I honestly think that that is the easiest and most satisfying solution, because it means we can also display our images to their fullest glory both in print and on the screen. Some very light, overexposed areas, and some dark, underexposed areas, never is a problem in a picture, because even the human eye struggles with large dynamic ranges. Just that the human eye dynamically adapts itself to the environmental light conditions without us noticing this adaptation a lot (unless we consciously do observe this, or step out from th every dark to the very bright or vice versa), and quite quickly too, but it is not how we really physically see the environment. Our brain does process and adjust things rapidly enough most of the time that we don't notice this.
BTW, in PP, even adjusting contrast, brightness and saturation often does the trick, either to expand or to compress the dynamic range the camera is capable of registering and making it fit the enviroment for display. For best results provided of course that exposure was done to fit with the end result. It honestly is amazing what one can get out of digital compared to film. From my experience, film actually doesn't come close, regardless of what some people say. The main difference between the two media, other than differences in DR and the actual curve, is the fact that film favours the top end of the exposure curve for detail, due to its transparant nature vs the blown out nature of digital at the high DR end, and digital the bottom end of the curve, due to the fact it still manages to retain detail at the lower end, where film just gets totally opaque.
Also note that with higher DR cameras, with fully utilized DR, the pictures will have a distinctive HDR look, as the viewing media can't handle this DR, and neither can the human eye, thus requiring DR compression to fit. Although the human eye is supposed to be able to handle a contrast range of about 1:1,000,000,000 (about 24 stops), this is not the actual DR range as we can see in a single instant, without any processing by our own hardware, both the iris (aperture) and sensitivity. Do note that this means we can't see this range in one go either, because we would have to simultaneously have our irises wide open and completely closed, and adjusted to high and low sensitivity. In reality we can handle about 10-14 stops in a single go (estimates), without processing or adjustments. In short, for this instantaneous type of looking, a digital camera is already there, considering digital can handle currently up to 13.5 stops of DR in some models (and 10 to 12 in the better ones anyway). And directly compared to th eye, this still means a camera can handle, for handheld shutter speeds of 1/60s and up, let's say, a similar "total DR" of about 23 to almost 25 stops (F/1.4 to F/22, 1/60s to 1/8000s, iso 100 to 800 without major loss of DR, assuming 10-13.5 stops of DR, exposed in the middle, i.e., 8 + 7 + 3 + 5, max. 7 = 23 to max. 25) , which is close if not the same, just not almost instantaneous or automatic. Use a tripod, and longer shutter speeds, and you get even more. Not DR as you want it, I know, but that is how DR in an eye works too.
In short, if you do want more DR, for example for landscapes in the bright sun with, e.g., a path leading into a dark forest in the shadows, where you'd want to see details in both simultaneously, this isn't going to be possible soon, but then, the human eye can't do both simultaneously either. The human eye works like film really, e.g., it will correct for the highest DR values first, so that we can still see something in the brightest parts, while the darkest parts will completely clip, i.e., will show no detail at all. The challenge is to get digital to work in a similar way, where it fundamentally does the opposite, namely clip the highlights first.
Hence exposing to the right with digital, i.e, the highest DR where important stuff doesn't get clipped yet. That is IOW really an emulation of what our eyes and brain do <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='B)' />. Of course, when a human in that case concentrates on the dark forest, and one exposes the camera for the same, it'll look very similar.
Naturally, one could always do HDR, but that will generally look like (overprocessed) HDR too in most cases, even when done from a single RAW (and the latter is really a limit of the viewing medium). So, do we really need more DR? Or do we need/want to be able to record more intermediate tonal values? I really wonder <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='B)' />. However, in both cases we need better and faster AD converters and faster and better image processors in our cameras, and probably also better and faster computers, larger hard disks, new standard file formats, better monitors, better paper DR, etc. <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' />.
Kind regards, Wim
Very informative post, thanks, Wim!
All discussions of resolution aside, I feel that with a Canon 5D MK II I am at a level that is perfectly adequate (prints above A2 are very rarely called for) - but what I really want is more dynamic range. Maybe I'm wrong here, but I feel that the industry is selling their new technology on the strength of megapixels because it's easier than improving dynamic range.
[/quote]
Thank you, Pinhole, it's a pleasure.
To a degree you're right. There are also several aspects to this. Sensor DR really is already better than film, at least in RAW files, namely approximately 10 stops, and if you push it you can get to about 12.
In order to get more out of a sensor, we actually need better AD and related circuitry. Current sensors, especially FF ones, are already capable of approximately 15-16 stops of DR, but making a good AD converter at a reasonable price that can handle this, especially at the noise levels required, is still a long way out of scope. I have been told there actually are cameras out there than can do approximately 16 real stops of DR, but those are rather expensive, and only made to order. Eventually, the technology will permeate down to general use, just like we see and have seen with, e.g., car improvements like disc brakes. I do think this still is some time off however.
A second thing to note is that in print, due to th elimited DR possible as paper can only be so reflective and inks only so black, you lose a lot of this DR, and in order to make prints that look right, you somehow need to compress the DR into a smaller space, in a way similar to what we used the Zone System in the past for. And even on screen this is true. Thsi does fool th ehuman eye and brain to think we actually see what was there in the original scene BTW.
I would therefore suggest that if you feel you are lacking in this area, to pick up some reading on the Zone System. There even are books on how to apply this with digital, and take it from there. I honestly think that that is the easiest and most satisfying solution, because it means we can also display our images to their fullest glory both in print and on the screen. Some very light, overexposed areas, and some dark, underexposed areas, never is a problem in a picture, because even the human eye struggles with large dynamic ranges. Just that the human eye dynamically adapts itself to the environmental light conditions without us noticing this adaptation a lot (unless we consciously do observe this, or step out from th every dark to the very bright or vice versa), and quite quickly too, but it is not how we really physically see the environment. Our brain does process and adjust things rapidly enough most of the time that we don't notice this.
BTW, in PP, even adjusting contrast, brightness and saturation often does the trick, either to expand or to compress the dynamic range the camera is capable of registering and making it fit the enviroment for display. For best results provided of course that exposure was done to fit with the end result. It honestly is amazing what one can get out of digital compared to film. From my experience, film actually doesn't come close, regardless of what some people say. The main difference between the two media, other than differences in DR and the actual curve, is the fact that film favours the top end of the exposure curve for detail, due to its transparant nature vs the blown out nature of digital at the high DR end, and digital the bottom end of the curve, due to the fact it still manages to retain detail at the lower end, where film just gets totally opaque.
Also note that with higher DR cameras, with fully utilized DR, the pictures will have a distinctive HDR look, as the viewing media can't handle this DR, and neither can the human eye, thus requiring DR compression to fit. Although the human eye is supposed to be able to handle a contrast range of about 1:1,000,000,000 (about 24 stops), this is not the actual DR range as we can see in a single instant, without any processing by our own hardware, both the iris (aperture) and sensitivity. Do note that this means we can't see this range in one go either, because we would have to simultaneously have our irises wide open and completely closed, and adjusted to high and low sensitivity. In reality we can handle about 10-14 stops in a single go (estimates), without processing or adjustments. In short, for this instantaneous type of looking, a digital camera is already there, considering digital can handle currently up to 13.5 stops of DR in some models (and 10 to 12 in the better ones anyway). And directly compared to th eye, this still means a camera can handle, for handheld shutter speeds of 1/60s and up, let's say, a similar "total DR" of about 23 to almost 25 stops (F/1.4 to F/22, 1/60s to 1/8000s, iso 100 to 800 without major loss of DR, assuming 10-13.5 stops of DR, exposed in the middle, i.e., 8 + 7 + 3 + 5, max. 7 = 23 to max. 25) , which is close if not the same, just not almost instantaneous or automatic. Use a tripod, and longer shutter speeds, and you get even more. Not DR as you want it, I know, but that is how DR in an eye works too.
In short, if you do want more DR, for example for landscapes in the bright sun with, e.g., a path leading into a dark forest in the shadows, where you'd want to see details in both simultaneously, this isn't going to be possible soon, but then, the human eye can't do both simultaneously either. The human eye works like film really, e.g., it will correct for the highest DR values first, so that we can still see something in the brightest parts, while the darkest parts will completely clip, i.e., will show no detail at all. The challenge is to get digital to work in a similar way, where it fundamentally does the opposite, namely clip the highlights first.
Hence exposing to the right with digital, i.e, the highest DR where important stuff doesn't get clipped yet. That is IOW really an emulation of what our eyes and brain do <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='B)' />. Of course, when a human in that case concentrates on the dark forest, and one exposes the camera for the same, it'll look very similar.
Naturally, one could always do HDR, but that will generally look like (overprocessed) HDR too in most cases, even when done from a single RAW (and the latter is really a limit of the viewing medium). So, do we really need more DR? Or do we need/want to be able to record more intermediate tonal values? I really wonder <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='B)' />. However, in both cases we need better and faster AD converters and faster and better image processors in our cameras, and probably also better and faster computers, larger hard disks, new standard file formats, better monitors, better paper DR, etc. <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' />.Kind regards, Wim
Gear: Canon EOS R with 3 primes and 2 zooms, 4 EF-R adapters, Canon EOS 5 (analog), 9 Canon EF primes, a lone Canon EF zoom, 2 extenders, 2 converters, tubes; Olympus OM-D 1 Mk II & Pen F with 12 primes, 6 zooms, and 3 Metabones EF-MFT adapters ....