Visual Calibration can also be referred to as an oxymoron. It is a contradictory notion that or eyes can be used for precision calibration. How much coffee have you had before you try this, how much alcohol the night before or that afternoon? Are you wearing a red shirt in a bright room, which is now reflecting lots of red onto the display? Using a colorimeter will help you set your device to industry standards for luminance and then you can build your own profile with its own gamut and characteristics, both good and bad, for that display. Then Photoshop will know how your display conveys color meaning. See this link from MIT on how easily the eye can be fooled. http://web.mit.edu/persci/people/adelson/checkershadow_illusion.html David Wollmann