Under normal viewing environments, where even the black state of all displays is not truly black anymore due to ambient light reflecting off the screen, the effective contrast may be no more than 80:1. However, that does not mean that display itself will only give a 0.5 million color performance. One would simply see 16.8 million colors with some ambient background. For example, imagine looking at your computer monitor in a completely dark room versus the same with the lights on. With the lights on, you can still see all the colors, but the dark areas will not be as dark.
We state two contrast numbers, one for the capability of our microdisplays (1200:1) and one for the HMD system (100:1) which accounts for the LEDs that illuminate our LCoS displays. This means it will display 16.8 million colors even with 10% transparency. Our HMD was designed to provide a Full HD viewing experience without disconnecting the users from their surroundings and to inspire augmented reality applications.