An 8 bit image with a color palette ranging from white to black. You can have a 24 bit black and white image but that is not a grey scale. Grey scale is available from the Colors Menu.
Ability of any projector to depict a colour range between black and white in consideration of many interjacent grey scales.
Test Pattern in the form of a luminance staircase (increasing or decreasing ). Commonly used to check the display's dynamic grey balance (grey scale tracking).