garypayton Posted April 18, 2012 Share Posted April 18, 2012 I'm interested too...so the principle (to put it simple) is to isolate the skintone when you color correct the rest of the footage right? Quote Link to comment Share on other sites More sharing options...
see ya Posted April 18, 2012 Share Posted April 18, 2012 [quote author=yellow link=topic=290.msg4267#msg4267 date=1334779674] Interpretation and subjective generalisation. With regard to Canon (any model) vs GH2 skin tone comment & video is actually YCbCr not RGB comment.[/quote] [quote]I am sorry. English is not my native language. Are you saying that using RGB workspace means misinterpretation and results in bad colors? [/quote] Sorry, I was trying to leave my comment open for discussion and interpretation. I was suggesting that as a YCbCr to RGB color space conversion is done for those RGB scopes and the preview window that so much is judged from including making assertions that skin tone is better on Camera A than Camera B are all products of a interpretation of the native YCbCr source, even putting GH2 and Canon files in the same NLE project side by side proves nothing unless the conversion to RGB method can be assured and preferably controlled as each uses different methods in encoding. Hence the image to illustrate the variance depending on interpretation in conversion to RGB. Quote Link to comment Share on other sites More sharing options...
Axel Posted April 19, 2012 Share Posted April 19, 2012 @garypayton Yes. It is keying, like greenscreen, but more intricate, because you use a [u]range[/u] of tones (in [b]h[/b]ue, [b]s[/b]aturation and [b]l[/b]uma, the color picker is therefore called [i]HSL qualifier[/i] in Apples Color) instead of only one shrill Kermit color. You have to finetune the key very exactly. The secondary CC also always have a softening filter integrated to feather the matte. Google for [i]Sin City[/i], [i]Pleasantville[/i] or [i]Schindlers List[/i] tutorials. Because with the extreme effect of completely desaturating everything but one color you see it best. @yellow GH2s AVCHD and 5Ds H.264 both use YCbCr, and both are treated in an RGB environment (the colorspace of your NLE, your monitors). No differences to be expected from there. Correct me. Quote Link to comment Share on other sites More sharing options...
see ya Posted April 19, 2012 Share Posted April 19, 2012 [quote author=Axel link=topic=290.msg4295#msg4295 date=1334810129] @yellow GH2s AVCHD and 5Ds H.264 both use YCbCr, and both are treated in an RGB environment (the colorspace of your NLE, your monitors). No differences to be expected from there. Correct me. [/quote] Yes, however color matrix luma coefficients differ between sources GH2 is BT709, Canon's BT601 and Canon h264 has meta data in the header of the MOV's that signals 'full range' luma where as GH2's MTS doesn't. So in the conversion to RGB color matrix is used, if the wrong matrix is assumed by the NLE then pink hues shift to orange so affects skin tone. Full range flag causes decompressing codec to squeeze the full range luma into 16 - 235 at ingest. So there is room there for misinterpretation, not saying it's always that way, just that there are affecting factors between YCbCr native files and RGB preview and RGB based scopes. The image illustrates the various combinations of color matrix coefficients and luma handling possible leading to what could be incorrect assumptions on a cameras capability. Quote Link to comment Share on other sites More sharing options...
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