Does anyone know how the pixel size in a standard MBP relates to the pixel size in a Retina MBP? Now, I don't mean the pixel spacing (that is obvious - it is double). I mean the actual pixel size, discounting the black space around each pixel. I understand there is more black space in total area in the Retina display which requires a brighter backlight to achieve suitable display brightness. Does anyone have any figures on this? I have been unable to find with google.