what desides the color transformation?

:( i changed a same photo from cmyk to rgb in two different Macintosh, but got a different result, one is more blue then the other, why?
:confused: and i wonder that what parameters in Photoshop and System are affecting the color transformation?

The difference in color representation between any two systems can be caused by many different things. For one thing, no two monitors display color the same way, particularly if they've had different amounts of usage. Then, there are ColorSync profiles to consider...they'd need to be the same on both systems to have any hope of being the same (as judged at a professional level, anyway). These are just a couple things to consider, and there are many more.

I suggest you research as much as you can about color management systems and practice...and be prepared for a long haul. I've been studying it for years and still haven't fully nailed it down.

I musta missed this one...

µ23 digs deep!

I also wanted to add, that going into your color preferences in photoshop and turning off that photoshop color fixer upper thing-a-mah-bob.....
Damn.... I have NO idea what its called....

Lemme look!

Ok, in the "color settings" dialog, if on one machine you have different settings than the other machine.... fix that...

Also, in the section called "Color managment policies" in the "Color Settings" dialog, turn all that crap to "off" if it is on.... most people won't gain any kind of advantage by using it anyway. You have to know how to make use of it to get anything out of it.

TNKs for the detail answers upstairs.

i try ur mathods...in three Macintosh...
synchronize the ColorSync setting
in Control Panel,
in the Plug-in folder of Photoshop4,
(i use photoshop4 because of its fine display of CMYK for output)
and all about ColorSync in the preference of system,

Haha! what d u think i got?
*two of them come to a same result:
an CMYK orange color(M75\Y100) ->> R242, G95, B20;
and the info panel displays (M75\Y100) still.
by the way, one monitor of the above computer have been checked up by the scan-expert from an output center.

*the third Mac comes to be a different one:
M75Y100 ->> R230, G92, B23
info panel displays (M75\Y99).

@_@ feel quite disappointed......
did i neglect sth?:o

Two out of three ain't bad, :D

that third machine must have something different from the other two,

OS version

Colorsync version

Has is got a scanner/scanner software installed that the others do not have? Some scanner software will change the machine's gamut settings to meet what it thinks you should have)

The RGB differences are equal to the CMYK differences by my calculations, so the answer is there....you just have to find it.

Yes!

u v told the just right thing!

two of them are installed in the same system and same version colorsync,
which different from the third.

n...
the first two Mac are connected to different type of scanner, one is Umax n the other Microtek, but it makes no difference to their photoshop color trasformation:-)

i w stydy on it continuously.
Thanks,tornupinside.:D