A wide variety of video projection technologies has been employed in domes, including Cathode Ray Tube (CRT), Digital Light Processing (DLP), Liquid Crystal Display (LCD), Liquid Crystal on Silicon (LCOS), and most recently, two varieties of laser projectors (the laser video projector entry describes one version of the technology).

For multi-projector systems in particular, display devices must have a low black level (i.e., project little or no light when no signal is sent to them) to allow for reasonable edge-blending between the different projector footprints. Otherwise, overlapping video images will have an additive effect, causing a complex pattern of grey to appear even when no image is being projected. This becomes particularly important for users in the planetarium field, who have a vested interest in projecting a dark night sky. The desire for projectors to “go to black” has resulted in continued use of CRT technology, even as newer and less expensive technologies have emerged.

LCD projectors have fundamental limits on their ability to project true black as well as light, which has tended to limit their use in planetariums. LCOS and modified LCOS projectors have improved on LCD contrast ratios while also eliminating the “screen door” effect of small gaps between LCD pixels. “Dark chip” DLP projectors improve on the standard DLP design and can offer relatively inexpensive solution with bright images, but the black level requires physical baffling of the projectors. As the technology matures and reduces in price, laser projection looks promising for dome projection as it offers bright images, large dynamic range and a very wide color space.