gdanmitchell
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 p.5 #3 · p.5 #3 · Does a "no frills" travel camera exist, Canon or otherwise? | |
gdanmitchell wrote:
And when you display your images on social media and in email as jpg images you are not getting that full range anyway – that file format has less dynamic range than the raw files from your camera.
then…
melcat wrote:
No it doesn’t. The dynamic range is retained, by transforming according to a log curve (hence “gamma”, the log base, and “linear” as in “linear DNG”, the untransformed curve). This does cause a loss of gradation between adjacent brightness values, but the log curve means that the gradation loss is concentrated in brightness values that humans find hard to distinguish anyway.
I urge you to actually try this with a maximum DR raw file — not one with a few points at the extremes, but one in which large portions of the image are at the extreme ends of the DR.
Assuming that you adjust exposure so as to avoid blowing out the bright end (that’s really important, as you cannot recover blown highlights) you will find that the far dark end of the range is nearly black. There’s data there, and there’s less noise with the high DR systems, so you can recover it in post, but it isn’t going to look the way you want until you do that post—processing.
If you simply apply a curve to the whole image to expand the luminosity values at the low end and then output to print or jpg, etc. you lose contrast in other parts of the dynamic range and end up with very flat looking images. That’s why working with high DR files generally requires significant post-processing.
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