4-Star gets RealD technology

Installers are working this week at 4-Star Cinema to bring Kilgore the latest in silverscreen technology.

The new setup going into one of the four theaters is commonly know as 3-D or digital viewing, but is actually a RealD technology.

The technique that RealD uses is unlike the traditional method of 3-D imaging which uses linearly polarized glasses.

The traditional 3-D method works by projecting two differently linearly polarized images onto the same screen, polarized at plus-45 degrees and negative- 45 degrees from the horizontal, which are then filtered through linearly polarized glasses worn by the audience. This type of 3- D imaging requires two projectors, and suffers from visible double-imaging if the head is tilted to the side which places the glasses at an less than optimal angle.

RealD uses a single projector that alternately projects the right-eye frame and left-eye frame, and circularly polarizes these frames, clockwise for the right-eye and counterclockwise for the left-eye, using a liquidcrystal screen placed in front of the projector lens. Circularly polarized glasses make sure each eye sees only its own picture, even if the head is tilted. The high frame rate of 72 frames per second per eye, makes sure the image looks continuous.

In RealD Cinema, each frame is projected three times to reduce flicker, as the source video is usually 24 frames per second. The result is a seamless 3-D picture that seems to extend behind and in front of the screen itself.

The first RealD film slated for performance is "Bolt," an animated feature starring John Travolta in the lead voice role.