Hello Mr. Ivanov, as I know since Photoshop 5.0 the Color Engine uses ICC-Colormanagement. Since PS6 it is implemented in a "controllable" way. Using ICC-Colormangement with input and monitor-profiles (ECI-RGB is a monitor-profile technically) the conversion is always done through the PCS (even if you check the "no colormanagement" option). The PCS is XYZ in ECI-RGB. So the answer to your question is no, PS does the conversion through XYZ not Lab. But in real life there is no real difference if the PCS is Lab or XYZ. Best regards, Claas Bickeböller Am 31.03.2007 um 08:56 schrieb Borislav Ivanov: