If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
|
Thread Tools | Display Modes |
#12
|
|||
|
|||
"digital" flash mode (no actual flash fired) HP945
Michael Meissner wrote:
lid writes: Michael Meissner wrote: The problem is most digital cameras have a lot less range than print films do, between dark and light. Slide films have the same sort of problems, and the solution is typically the same (expose to avoid burning out the highlights and bring out shadow detail in post processing). In the most common case of JPEG, there are only 8 bits (values 0-255) for each color per pixel. Yeah, but usually those 8 bits represent a value that you raise to the power 2.2 to get luminance. When you work that out, 8 bits is a heck of a dynamic range. The classic counterexample is shooting weddings, and trying to get detail in both the bride's white dress and the groom's black tux. But that's not really a counterexample: there's no way that the ratio of tux/dress exceeds the dynamic range of a JPEG encoded at gamma 2.2. The limiting factor is still sensor noise. From what I've read, most digital cameras give you the range of slide film, but print film still gives more latitude. From what I can see, digital sensors (or at least those in DSLRs) have more dynamic range than transparencies but less than print film. It may be that with a drum scanner you can squeeze a bit more out of a transparency. I believe in general you only get that extended range in DSLRs when you use raw mode, which for many cameras can give you 10-12 bits of precision. What raw gives you is linear encoding, at least with CCDs. That gives you an opportunity to use curves somehow to squeeze that huge dynamic range into that of a print -- which has Dmax 1.2 if you're lucky. I suspect within 5 years or so, there will be a shift to using 16-bit formats in cameras. Actively cooled sensors, maybe? Andrew. |
#13
|
|||
|
|||
"digital" flash mode (no actual flash fired) HP945
Michael Meissner wrote:
lid writes: Michael Meissner wrote: The problem is most digital cameras have a lot less range than print films do, between dark and light. Slide films have the same sort of problems, and the solution is typically the same (expose to avoid burning out the highlights and bring out shadow detail in post processing). In the most common case of JPEG, there are only 8 bits (values 0-255) for each color per pixel. Yeah, but usually those 8 bits represent a value that you raise to the power 2.2 to get luminance. When you work that out, 8 bits is a heck of a dynamic range. The classic counterexample is shooting weddings, and trying to get detail in both the bride's white dress and the groom's black tux. But that's not really a counterexample: there's no way that the ratio of tux/dress exceeds the dynamic range of a JPEG encoded at gamma 2.2. The limiting factor is still sensor noise. From what I've read, most digital cameras give you the range of slide film, but print film still gives more latitude. From what I can see, digital sensors (or at least those in DSLRs) have more dynamic range than transparencies but less than print film. It may be that with a drum scanner you can squeeze a bit more out of a transparency. I believe in general you only get that extended range in DSLRs when you use raw mode, which for many cameras can give you 10-12 bits of precision. What raw gives you is linear encoding, at least with CCDs. That gives you an opportunity to use curves somehow to squeeze that huge dynamic range into that of a print -- which has Dmax 1.2 if you're lucky. I suspect within 5 years or so, there will be a shift to using 16-bit formats in cameras. Actively cooled sensors, maybe? Andrew. |
#14
|
|||
|
|||
"digital" flash mode (no actual flash fired) HP945
lid writes:
Michael Meissner wrote: lid writes: Michael Meissner wrote: The problem is most digital cameras have a lot less range than print films do, between dark and light. Slide films have the same sort of problems, and the solution is typically the same (expose to avoid burning out the highlights and bring out shadow detail in post processing). In the most common case of JPEG, there are only 8 bits (values 0-255) for each color per pixel. Yeah, but usually those 8 bits represent a value that you raise to the power 2.2 to get luminance. When you work that out, 8 bits is a heck of a dynamic range. The classic counterexample is shooting weddings, and trying to get detail in both the bride's white dress and the groom's black tux. But that's not really a counterexample: there's no way that the ratio of tux/dress exceeds the dynamic range of a JPEG encoded at gamma 2.2. The limiting factor is still sensor noise. You sound like you know more about it than I do, but I do know weddings can stress most cameras, and usually you have to underexpose digitals so that the highlights aren't blown. From what I've read, most digital cameras give you the range of slide film, but print film still gives more latitude. From what I can see, digital sensors (or at least those in DSLRs) have more dynamic range than transparencies but less than print film. It may be that with a drum scanner you can squeeze a bit more out of a transparency. I believe in general you only get that extended range in DSLRs when you use raw mode, which for many cameras can give you 10-12 bits of precision. What raw gives you is linear encoding, at least with CCDs. That gives you an opportunity to use curves somehow to squeeze that huge dynamic range into that of a print -- which has Dmax 1.2 if you're lucky. I suspect within 5 years or so, there will be a shift to using 16-bit formats in cameras. I was just speculating that if you go past 8 bits of precision, the next format is 16 bits -- even if you only have 12 bits worth of precision from the camera. Actively cooled sensors, maybe? Perhaps. -- Michael Meissner email: http://www.the-meissners.org |
|
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Basic Minolta flash questions | Dave Yuhas | 35mm Photo Equipment | 5 | June 28th 04 05:05 PM |
Digital Imaging vs. (Digital and Film) Photography | Bob Monaghan | Medium Format Photography Equipment | 9 | June 19th 04 05:48 PM |
Which is better? digital cameras or older crappy cameras thatuse film? | Michael Weinstein, M.D. | In The Darkroom | 13 | January 24th 04 09:51 PM |
Which is better? digital cameras or older crappy cameras that use film? | [email protected] | Film & Labs | 20 | January 24th 04 09:51 PM |