When it comes to cinema screens, there have been various attempts to change the screen surface makeup over the years, but principally the screen has been White or silver-white. This is fine as far as reflecting the projector light back into the room for people to see the images, and great for an even colour balance, however inevitably the image black areas are governed by the white screen material, and how black it looks is controlled by light being reflected back from the room to the screen again. The new Black Diamond material from Screen Innovations, is fundamentally a neutral dark grey colour to look at, and it is designed to throw the projection illumination out into the room, however to absorb ambient light coming in from the side. The result is that the black level of the image is now governed by a dark grey screen, and is far less susceptible to ambient light coming in from the side.
The long and short of it is the image you see has a far greater contrast ratio, and is more vivid and involving. If you like to watch your films with a little ambient light (or even with the lights on), with a Black diamond screen, the image looks far less washed out than with a conventional white screen. See these neat demonstrations in a room with high ambient light, and in a darkened room:
Black Diamond Contrast Comparison from Screen Innovations on Vimeo.
Black Diamond Screen Dark Room from Screen Innovations on Vimeo.