03-08-2011, 07:35 AM
[quote name='genotypewriter' timestamp='1299550000' post='6592']
It's difficult to expect a linear outcome when most things aren't linear.
Sensors for example have 3 colour channels (as we know) and all three should have different response curves (efficiency that varies with the amount of light going in). A "decent" amount of light is necessary for the "ordinary" response case that we know of but if the image is underexposed (to be pushed in post later), I'm sure the response will not be mathematically proportional to reduction in actual exposure.
The above will also lead to a change in colors (hue and saturation, regardless of brightness) depending on the exposure (because the 3 channels have independent response curves). So there can be colour shifts depending on the level of exposure and maybe ACR corrects these in a way which results in images that are slightly different to properly exposed shots. Or maybe ACR doesn't correct them at all. Either way, you're bound to see a difference.
GTW
[/quote]
Thanks for the explanation. It's obvious that increasing ISO is the better alternative.
Serkan
It's difficult to expect a linear outcome when most things aren't linear.
Sensors for example have 3 colour channels (as we know) and all three should have different response curves (efficiency that varies with the amount of light going in). A "decent" amount of light is necessary for the "ordinary" response case that we know of but if the image is underexposed (to be pushed in post later), I'm sure the response will not be mathematically proportional to reduction in actual exposure.
The above will also lead to a change in colors (hue and saturation, regardless of brightness) depending on the exposure (because the 3 channels have independent response curves). So there can be colour shifts depending on the level of exposure and maybe ACR corrects these in a way which results in images that are slightly different to properly exposed shots. Or maybe ACR doesn't correct them at all. Either way, you're bound to see a difference.
GTW
[/quote]
Thanks for the explanation. It's obvious that increasing ISO is the better alternative.
Serkan