somewhat offtopic question, is bokeh really just depth of field? Or do I just know dumb digiphotogs who use it as a synonym for depth of field? I could have sworn it was more specific to the lens and aperture than just "the fuzzy out of focus bit of the picture".
Dave Miller said:Strange really, for years most of us have been chasing detail via the purchase of ever more exotic glass, and hardware, bigger film and hang the expense, but now the digi-camp are trying to catch up it seems to be wrong. I wonder why?
(how it works, very roughly: if you make a blurred copy neg from a neg (use an enlarger or stat camera out of focus and 1::1 -- or make two copies, one sharp and one not), then sandwich them together, the areas where they are teh same - no detail - will be black. The areas where the blurred and focused images are different - the details - will let light through. Based on this you can start to use the mark (or its inverse) for burning and dodging.....)
BTW, people (even in the digirealm) have started to catch on to the idea that wide-blur, low-intensity unsharp masking (and inverse masking) can recreate many of the tone mapping effects popular in "HDR" processing.
If She exists, She is in the photographer's eye, brain or heart.
The particular "look" of HDR images is tonal compression in the extreme areas. Thiscontext-sensitive tone-mapping requires a "deep" picture, but I see a lot of "HDR" images on flickr that are made from a single RAW file, which may in many cases have less tonal range than a color negThis doesn't seem right to me - these techniques are only going to work if the detail is present in the original digital file. The original purpose of HDR was to work around the fact that digital sensors are only 12-16 bit devices. As such, they have a very limited dynamic range. HDR allows you to take a few frames at different exposures and combine them into a digital file that has 32-bit pixels. With 32-bits, you have much much more dynamic range. Once you have that 32-bit file, I can see how an unsharp mask techniques can then be applied to get the effects you describe.
The particular "look" of HDR images is tonal compression in the extreme areas. Thiscontext-sensitive tone-mapping requires a "deep" picture, but I see a lot of "HDR" images on flickr that are made from a single RAW file, which may in many cases have less tonal range than a color neg
Ultimately, I think HDR will be replaced by Digital cameras with 32-bit sensors. Since current 12-14 bit digital cameras seem to have a dynamic range of about 5 stops, I would estimate that a 32-bit sensor would have a dynamic range of 10-11 stops.
Bit depth has nothing to do with dynamic range. It only has to do with the number of intermediate tones between extremes.
If a sensor can record detail over a 1000:1 brightness range (approx 10 stops), then increasing from 24 to 32 to 48 to 96 bits is not going to change the upper and lower limits of that range -- it will only change the number of intermediates.
To get a higher dynamic range, you need a physical sensor that is responsive over a greater range of light. Once you've accomplished that, then you'll need higher bit depth to accomodate all the data -- but it's the sensor and not the bit encoding that makes this possible.
The 32-bit files in HDR are necessary because each individual pixel holds the R/G/B information from 5, 8, 10, etc individual captures. So you need extra bit depth just to hold all that data. But it's not the bit depth per se that creates the higher dynamic range -- it's the content of that pixel information that does.
True. Though I think the dynamic range of current digital cameras is pretty much fine. All they need to do is make the shadows far less noisy and make the highlights end much less abruptly. DSLRs already have a much greater latitude than slide film, and they're comparable to a negative with standard development.
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