I was at CompUSA a few days ago comparing the IMacs. I don't know if it was my eyes or the brightness was set differently but the 24" iMac was MUCH brighter than the 20" and 17" models. I will be purchasing an IMac this fall mainly for digital photography and videography. I know a good monitor is a must have for for the colors and picture quality when dealing in line of work. Are the 24s naturally brighter than the lower end models?