Znalazłem ciekawy wątek:
http://photography-on-the.net/forum/...p/t-70397.html
i 2 ciekawe spostrzeżenia rozmówców:
"..in Canon dSLRs, the histogram is really a "luminance" or brightness histogram derived from the green color channel only (since there are twice as many green pixels as others, this is a good proxy for the whole image). So, it does not tell you perfectly about exposure of red and blue channels... "
"I just copied an old CRW file to a CF card and displayed the histogram for it on my 10D and sure enough, it's only displaying the histogram for the green channel. The same image in Photoshop, displayed in RGB mode has three separate spikes, one for each of the colors. On the 10D, the only spike I see is the green spike."
...ciekawe co nie ?
Dodałem jeszcze 3:
"my 10D was displaying histogram information that was in the green channel only. Yes, it was displaying it as a luminance info but that info came from the green channel. How do I know that? Because that image had 3 distinct and separate spikes for the red, green and blue channels in PS. The luminance historgram shows a 3-spiked histogram in PS. The 10D only shows one and that spike matches the spike from the green channel.
Are you sure you were looking at the luminance histogram in PS? The default histogram in PS is RGB which is a cumulative sum of the red, green and blue histograms. You need to change the histogram mode in PS to Luminosity to display luminance."
Odpowiedz z cytatem