rgb vs srgb

dot_bat

Can anyone tell me what the preference color correction will do? at the moment i cant change any preference or i'll crash. im trying to save in rgb. i hate srgb, too small a gamut for print even for video and converting to cmyk from it is disappointing. will it save in rgb? if i remember correctly carrara in a previous incarnation saved in rgb or may be it was raydream

wetcircuit

dot_bat said:

Can anyone tell me what the preference color correction will do? at the moment i cant change any preference or i'll crash. im trying to save in rgb. i hate srgb, too small a gamut for print even for video and converting to cmyk from it is disappointing. will it save in rgb? if i remember correctly carrara in a previous incarnation saved in rgb or may be it was raydream

I believe that Carrara does NOT save to sRGB, unless that is an option under jpg...
Saving to Photoshop, Tiff, or PNG will give you RGBA

No one has ever explained what the option for color correction is under the Preferences. It's been asked before, and there is no mention of the option in the manual. However, logic suggests that since it is an option under Texture Spooling, it is related to some method of compression when using that function.

If I recall from the old forum, Texture Spooling was tested by the community and found to slow down renders if a large amount of memory is reserved. People recommended turning it on, but setting it to the lowest possible setting. Texture Spooling is a vestigial function when RAM was limited and hdd were slow.

Richard Haseltine

sRGB isn't a format, it's a colour space. On it's own, an RGB value doesn't specify a colour, you have to say what colour space you are using to get a specific colour; with colour management you profile your display (and input/output devices) so the system knows what colour they mean when sent or sending a particular set of numbers, and you choose a working colour space so that you know (in theory) what colour you are picking with particular RGB values, and the CMS then adjusts incoming and outgoing values to keep everything consistent. I don't know what the Carrara option is doing, given that the system isn't otherwise colour managed - possibly tagging output files.

dot_bat

thank you all for the response. ive been saving as a targa image for the 24 bit, not sure if fotoshop saves 24bit. but will try different file formats.
richard are you saying opening up a srgb in fotoshop and changing the profile to rgb will solve this for me? sounds reasonable but was not sure if all the information would be there, will have to see if opened in fotoshop if its color managed and then assign a profile. sorry for late response been traveling. thank you all again

Richard Haseltine

sRGB is RGB. It's just a question of what the colour values are taken to mean - you can get Photoshop to change the meaning by using the Edit>Assign Profile command (the location of which has changed over the versions of PS, but that's where it is in CS6).

dot_bat

srgb is a much narrower color space than rgb its not rgb. if im working in srgb im limited to that narrow color space but my monitor is capable of displaying the full gamut of rgb. right there im not using the optimum pallet available to me which is rgb and white point of 1.8. pc white point 2.2 and native color space srgb very dark on a mac. just changing the profile to rgb in fotoshop does not create the full spectrum of the wider gamut available in rgb it just maps the limited color space to that of rgb. my monitor is capable of displaying more colors than that of srgb. i realize that this is a pc monitor vs a mac. they changed the standard because most people thru out the world are on pcs and not able to display the full range of rgb on they're monitors and no color correction needed so its great for the web. but for print and video not intended expressly for the web or a pc monitor im not getting the full range of colors my monitor is capable of displaying and ultimately printing. . if carraras native color model is srgb its not giving me the full spectrum my monitor is capable of. what im saying is i would like the option of working in rgb so i can utilise the full gamut of what my monitor and printer are capable of. if im working on something for the web id still like to be able to work in rgb and later convert to the narrower srgb and lose color.
ok i just opened a file saved directly from carrara in fotoshop and it saves as an untagged rgb file so all is well. thanx

Richard Haseltine

RGB is not a colour space. sRGB is a colour space, a very narrow one as you say. Adobe RGB is another colour space, a much broader one (probably broader than your monitor can display; mine claims to be able to manage 97% of Adobe RGB). Having the image tagged sRGB doesn't change it, however - it's still a bunch of triplets specifying RGB values - all that tagging an image as sRGB does is tell the system how to interpret those values. Of course if the image is rendered in a wider gamut space and then converted to sRGB some values will change, depending on the conversion intent, with out of sRGB gamut values possibly being clipped to the nearest in gamut value, and if you then convert that to a wider gamut space such as Adobe RGB the values will change again, as the image data is squeezed into a more limited range of values in the middle of the colour space. But I don't believe Carrara does render in wide gamut and then clip, and certainly if you Assign to profile (instead of Converting to profile) the RGB values will not change - merely the way they are interpreted - so assigning Adobe RGB (or whatever you use) will give you the wide-gamut image you want. You could also simply turn colour management off (top option in Assign Profile), which will send the raw RGB values to your screen.

dot_bat

yes im sorry i meant adobe rgb. thanx for info. i was a little worried about it but i see what you are saying. thanx again