04-11-2012, 08:07 PM
Hi Frank,
[quote name='Frank' timestamp='1334127274' post='17428']
Thank you, Wim. I see it better now. As far as I understand, the Zone System technique itself does compress the DR, what it does in the recording process is to "map" the tone of the scene onto the film (more or less) in a way designed by the photographer. So, when you say "Using Zone System techniques it is possible to get 15-16 stops recorded at about 10 stops (or less) on film" I guess you also mean using the GND filters to compress the DR. Am I right?[/quote]
Actually, no. All I do is use common sense. I determine what I do want to be recorded at middle grey values, luminance wise, and that is what I expose for, possibly with some correction if I want to push up or pull down the image overall, IOW, depending on whether I want to compress dynamic range, or extend it. IOW, I do exactly the same as I did with B&W film.
I don't use GND filters often - I find the effect to be only minimal whenever I need them. Intrinsic recordable DR of a dslr sensor, APS-C or FF, already is beyond B&W. Any B&W film with 14 stops of DR generally has very low contrast, which means it is a pain to use except for night shots. 10 stops is a more normal value, from blackest black to usable whitest white before blowing out. The difference with film really is that the lower end and higher end of the tonal curve gets flat very quickly, so in a way there already is some (local) DR compression taking place, whereas generally speaking sensors do not do this, or not as strongly.
Furthermore, at medium to high contrast, the human eye doesn't see detail in darker areas, or in brighter areas, certainly not simultaneously in the darker and lighter areas. This is why B&W film is more natural to the human eye, with the dark parts (in print) getting so dense very quickly that no detail can really be seen in the last 2 to 2 1/2 stops of DR. Digital is more comvenient here, because although it is the area with least data, there tends to be more here than with film. Furthermore, in the case of noise, it can be ignored very easily without really affecting the final image.
The bright end has ample data in digital, just that beyond a full sensor site well, data gets lost, where with film it peters out at a slower and slower pace - no sharp cut-off here.
So the trick is to expose properly, in such a way that all the highlights which one wants to keep are spared from blowing out. And compressing or extending the DR to get the correct tonal range for printing can be achieved later, by "developing" the RAW. With film it is more complex, because one really needs to know the possibilities and latitude of the film used very well, and the interaction with various solution strengths of the developer used, including varying developing times. Essentially I used to use very short strips of film, 5 frames (which is the shortest film strip in a cassette one can use with a 35 mm slr), and expose and develop according to the result I wanted to achieve. Overexpose and underdevelop for a high contrast situation, and underexpose and overdevelop with low contrast (exposures all calculated based on measurements with my home-built 1/2 degree spotmeter <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' />). And then still burn and dodge if and where required, whereas with digital this is much simpler. Plus, one can create an image that is perfect to print and print it many times, whereas with film and the wet process that is much more difficult, if not impossible. In short, what took me hours to do with film, takes probably about 25% of the time with digital, if not less, and is very easily repeatable, unlike with film.
And 10 or 12 stops of DR is more than plenty to get the results required, although I do suspect that if pushed, a reasonably decent dslr really does manage 14 stops, based on the results I see myself (from RAW that is, and compared to the results from film).
IOW, I don't normally shoot HDR, but still use the general techniques of the modified Zone System I developed 30+ years ago for my own use, modified again for use with digital. And HDR, as in several differently exposed shots, I only use if I want to get an effect I would otherwise not be able to get. Essentially stuff no film can capture either. I've shot a few landscapes like that, with the sun quite high and bright still, and showing up in the image. I guess a 10-stop GND filter could make a difference here, but first of all I don't have one (don't even know if one exists), plus the cut-off point/line even with gradual filters is too abrupt - with HDR shots tis transition is much more easily controllable at specific luminance transitions.
So far my 2c <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='' />.
Kind regards, Wim
[quote name='Frank' timestamp='1334127274' post='17428']
Thank you, Wim. I see it better now. As far as I understand, the Zone System technique itself does compress the DR, what it does in the recording process is to "map" the tone of the scene onto the film (more or less) in a way designed by the photographer. So, when you say "Using Zone System techniques it is possible to get 15-16 stops recorded at about 10 stops (or less) on film" I guess you also mean using the GND filters to compress the DR. Am I right?[/quote]
Actually, no. All I do is use common sense. I determine what I do want to be recorded at middle grey values, luminance wise, and that is what I expose for, possibly with some correction if I want to push up or pull down the image overall, IOW, depending on whether I want to compress dynamic range, or extend it. IOW, I do exactly the same as I did with B&W film.
Quote:So, if GND filters (or digital HDR) are used, the DR that can be recorded by films/sensors are extended. Without these DR compression techniques, the "intrinsic recordable DR" of modern digital sensors indeed already exceeds the "intrinsic recordable DR" of even B&W films, if I understand your comments correctly.
Best regards,
Frank
I don't use GND filters often - I find the effect to be only minimal whenever I need them. Intrinsic recordable DR of a dslr sensor, APS-C or FF, already is beyond B&W. Any B&W film with 14 stops of DR generally has very low contrast, which means it is a pain to use except for night shots. 10 stops is a more normal value, from blackest black to usable whitest white before blowing out. The difference with film really is that the lower end and higher end of the tonal curve gets flat very quickly, so in a way there already is some (local) DR compression taking place, whereas generally speaking sensors do not do this, or not as strongly.
Furthermore, at medium to high contrast, the human eye doesn't see detail in darker areas, or in brighter areas, certainly not simultaneously in the darker and lighter areas. This is why B&W film is more natural to the human eye, with the dark parts (in print) getting so dense very quickly that no detail can really be seen in the last 2 to 2 1/2 stops of DR. Digital is more comvenient here, because although it is the area with least data, there tends to be more here than with film. Furthermore, in the case of noise, it can be ignored very easily without really affecting the final image.
The bright end has ample data in digital, just that beyond a full sensor site well, data gets lost, where with film it peters out at a slower and slower pace - no sharp cut-off here.
So the trick is to expose properly, in such a way that all the highlights which one wants to keep are spared from blowing out. And compressing or extending the DR to get the correct tonal range for printing can be achieved later, by "developing" the RAW. With film it is more complex, because one really needs to know the possibilities and latitude of the film used very well, and the interaction with various solution strengths of the developer used, including varying developing times. Essentially I used to use very short strips of film, 5 frames (which is the shortest film strip in a cassette one can use with a 35 mm slr), and expose and develop according to the result I wanted to achieve. Overexpose and underdevelop for a high contrast situation, and underexpose and overdevelop with low contrast (exposures all calculated based on measurements with my home-built 1/2 degree spotmeter <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' />). And then still burn and dodge if and where required, whereas with digital this is much simpler. Plus, one can create an image that is perfect to print and print it many times, whereas with film and the wet process that is much more difficult, if not impossible. In short, what took me hours to do with film, takes probably about 25% of the time with digital, if not less, and is very easily repeatable, unlike with film. And 10 or 12 stops of DR is more than plenty to get the results required, although I do suspect that if pushed, a reasonably decent dslr really does manage 14 stops, based on the results I see myself (from RAW that is, and compared to the results from film).
IOW, I don't normally shoot HDR, but still use the general techniques of the modified Zone System I developed 30+ years ago for my own use, modified again for use with digital. And HDR, as in several differently exposed shots, I only use if I want to get an effect I would otherwise not be able to get. Essentially stuff no film can capture either. I've shot a few landscapes like that, with the sun quite high and bright still, and showing up in the image. I guess a 10-stop GND filter could make a difference here, but first of all I don't have one (don't even know if one exists), plus the cut-off point/line even with gradual filters is too abrupt - with HDR shots tis transition is much more easily controllable at specific luminance transitions.
So far my 2c <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 ....