Classified according to the size of the projection screen
Screen format is also termed as “Aspect Ratio”, which defines relative measurements between screen width and screen height. Each projection method has its particular width-to-height ratio.
Currently the most common format is the “video” and “HDTV” format. If only one projection format will be used, screen height may be based on its aspect ratio. If more than one format will be used, screen aspect ratio must be adjusted accordingly.
Note: For Multi-Format projection application, the screen height has to follow the larger aspect ratio height.
The following table describes the ratio of the screen with the format:
| Video Format | 1:1.33 (4:3) |
| HDTV | 1:1.77 (16:9) |
| Wide Screen | 1:1.85 |
| Cinemascope | 1:2.35 |
| Overhead projector/Slide projector | 1:1 |
| Vista(Europe) | 1:1.66 (5:3) |
| Vista(America) | 1:1.85 |
| 16mm Film, 35mm Motion Picture/Filmstrip | 1:1.33 |
| 70mm Motion Picture | 1:2.18 |
