Like the seating location, the projection booth is accurately placed in relation to the cinema screen in every THX Certified Cinema. If the projection booth is not correctly installed in proportion to the cinema screen, the projected image will have a keystone or trapezoid onscreen effect.

In a THX Certified Cinema, the projection booth is accurately placed in relation to the screen – delivering an image with little or no distortion.	Improper projection booth placement results in many viewing issues, including a severe keystone or trapezoid effect.