The cathode ray tube projector works just like in the good ol’ television sets. The projector consists of three tubes, each dedicated to one of the primary colors; a lamp; a circuit board to manage the video signal; and a set of lenses to focus and amplify the light beamed from the lamp through the tubes. Since the image is formed by electrons horizontally scanning lines and not pixels being lit or unlit, the resolution is not pixel-limited like in other rival technologies as LCD or DLP. CRT projectors can be found in college auditoriums and movie theaters, where they’re used to display commercials prior to the main feature.

Model example: CRT projectors are currently hard to find. Sony Superbright VPH-1031 was a popular model many years ago.

Strong points

• Long lifetime (20,000 hours against 1,000 or 2,000 of rival technologies).
• Greater black level than LCD and DLP based projectors.
• High resolution limit (1920x1200 pixels).

Weak points

• Very heavy and bulky.
• Requires a very dark viewing room.
• Prone to color divergence if not finely tuned.