On 4 Sep 2004 at 0:18, David Mann wrote: > I haven't looked at ColorMatch RGB but ProPhoto RGB is by far the > largest colour space I've ever seen. Adobe 1998 is a little bigger > than sRGB, mainly in the green channel (which includes cyan). Adobe's > is optimised for the publishing industry, and sRGB was created to > represent the phosphors of most computer monitors
I found a great on-line utility for comparing ICC gamuts using 3D plots via VRML: http://www.iccview.de/index_eng.htm Using this utility it's evident that even AdobeRGB clips the printable gumut of an Epson 2100 printer. > Colour management is all about preserving colour > so from that perspective it is best to use a very large bit depth. > > Increasing bit depth requires more memory and disk space to store, and > more CPU to process. This all costs money so we don't want to do this > unless it's really necessary, so for best results it's important to > choose a working space that is big enough but not too big :) I've geared my new imaging work-station to be able to handle 16bit per channel colour images with ease so if utilizing a wide gumut CS and greater bit depth is the optimum solution that's likely what I'll employ. > In reality, there is little difference between sRGB and Adobe RGB. IMO > 8 bits per channel is fine in either of these spaces. Anything bigger > than Adobe RGB (eg EktaSpace or Pro Photo RGB) I would strongly > recommend storing at 16 bits per channel. WideGamutRGB seems like a hyper sized Adobe RGB and may be a better solution than ProPhoto RGB if working with 8bit per colour channel however it does seem to slightly clip a lot of colour spaces in a particular plane. > When printing it gets really messy as printer gamuts can be all over > the place. Inkjets are really CMYK devices so their gamuts don't match > up with RGB colour spaces. Soft proofing is very good but it does rely > on having a well calibrated a profiled monitor, and accurate printer > profile for your ink and paper combination. I found the concept presented at http://www.photogamut.org/ interesting, they have supposedly designed a real world universal profile which was modelled on real device data however when comparing the PhotoGamutRGB.icc with the Epson 2100 device profile there are significant indications of clipping. > http://www.digistar.com/~dmann/temp/profile_test/ > > That page only exists to test whether your web browser is colour > managed. I need to update the yes/no list as I've had some more > feedback (no more "yes" entries, unfortunately). It seems that only > Mac browsers support it as they tie into ColorSync at the system level. Yes unfortunately it appears that there isn't yet a colour savvy web Browser for the Windows platform, very sad indeed. > - Dave (one of these days I want to write a web-based guide that's both > informative and understandable). That would be good, currently it's all a bit daunting until you study scattered resources and finally manage to tie up all the seemingly un-related information. Thanks for the detailed reply. Cheers, Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
