-
What is Computer RGB?
A brief search on the internet suggests that Computer RGB may be a Sony Vegas creation, but I do not find a definition for it in the SVP Help facility. In Photoshop, there are several RGB color profiles such as sRGB IEC61966-2.1, Adobe RGB (1998), Apple RGB, Color Match RGB, and so on. Do any of these correspond to Vegas’s Computer RGB?
Does Computer RGB simply mean that the tones from 0-15 and 236-255 are allowed whereas in Studio RGB those tones are not allowed?
What color profile should Photoshop use for images coming to Vegas? What color space does Vegas use/assume in interpreting an RGB image? The difference, for example, between sRGB and Adobe RGB (1998) is that the Adobe profile maps to a larger color space. John Rofrano has suggested that the HDTV (Rec. 709) profile be used in Photoshop for Vegas images. However, this profile retains tones in the 0-15 and 236-255 ranges. So why use this profile? Does it map the tones from 16-235 to the values Vegas is using?
Along this same line, what is the difference between the Computer RGB to Studio RGB filter and the Sony Broadcast Color filter? Do they both do the same thing?
As you can see, I’m trying to wrap my mind around Vegas’s approach to color profiles.
-
2 Replies
-
Yes, ComputerRGB is simply 0-255. StudioRGB is 16-235. The 16-235 range is a legacy thing from analog days that stays around and complicates things. Legacy messes with us, like the weird 59.94 color tv field rate. B&W was 60.
Color profile is something else and defined by the device. Color TV has a specific profile. HDTV has a specific profile. In the computer world sRGB was created because it matched typical computer monitors reasonably.
The color profile says nothing about the numeric range but rather the absolute range of colors the profile is capable of. Once you have the absolute range and you have your numeric range, aka 8-bit, a tone curve(gamma), then you can map what absolute color a number 50 means for example.
-
Glenn Chan has written several excellent articles dealing with these questions.
https://www.glennchan.info/articles/articles.html
Reply to this Discussion! Login or Sign Up