I think it has to do with RGB being additive; adding all colors leads to white
and CMYK being subtractive. adding all colors leads to black RGB has so many more colors, it must be like clamping the bit depth but not quite. at any rate you loose something going one way, so it is a destructive workflow. On 12 February 2016 at 14:55, Jason S <jasonsta...@gmail.com> wrote: > It weird because if you take screenshot while in CMYK colorspace and paste > in an RGB image, > there you go, same blacklevels and everything as in CMYK but in RGB space. > > So would there be a way to "bake" color info from one colorspace to > another? > (assuming it's for hirez images, otherwise you could just take screenshots > :P ) > > I find it surprising that something like photoshop cant manage to make a > 1:1 conversion. > > > On 02/11/16 18:19, Sebastien Sterling wrote: > > Have been doing variants of this, to no great success, it doesn't seem to > want to change anything, haven't tried absolute colometric though, maybe i > will try that. The Web converter actually does have an effect, but not > perfect, it does bring the ultramarines back towards black. > > On 11 February 2016 at 23:02, Sven Constable <sixsi_l...@imagefront.de> > wrote: > >> Photoshop Edit->Convert To Profile >> >> You will see the source color space embedded in the original (if there is >> any) and the target color space. >> >> Choose one of the RGB spaces (eg. sRGB). >> >> Check blackpoint compensation and Relative Colometric. >> >> Tick Preview to see the result. >> >> Ideally you should see no to minimal color shifting, but this depends on >> the original color profile within the CMYK file. >> >> >> >> I'm pretty sure this what you'll get with that web based converter. >> >> However, your problem is not to get a close color match but to change >> colors (ultramarine blue to black). Not sure if this is possible without >> manual grading but you can try *unchecking black point compensation* and >> switch to *Absolute Colometric*. Then switch through the different color >> profiles and see if any of it will change the ultramarine blue back to >> black. >> >> If this worked somehow, do a second conversion to sRGB *with blackpoint >> compensation ON and relative colometric*. >> >> >> >> If this won't work, I think there is only manual color grading or have >> the client send you "correct" files. >> >> >> >> sven >> >> >> >> >> > >
