The ratio of the width to height of the picture image projected on the screen or printed on the film. The height is taken as unity (expressed as xx:1).
Film
The long established film aspect ratio is still retained for narrow gauge film is 4:3 (or a ratio of 1.33:1. With masking this is projected at a ratio of 1.37:1).
widescreen cinema presentation systems may have aspect ratios from 1.65:1 up to 2.55:1.
Video
The current television aspect ratio is 4:3. Early television systems were 5:4 to provide the maximum rectangle obtainable on the circular picture tubes then in use.^^ Wide screen television has an aspect ratio of 16:9.
Common Cinema Presentation Systems
| System | Aspect Ratio | Gauge | |
|---|---|---|---|
| Negative | |||
| Standard 16mm | 1.37:1 | 16mm | 16mm or Optical 35mm |
| Super 16mm | 1.65:1 | Extended 16mm | Optical and Masked 35mm |
| Standard 35mm Wide Screen | 1.37:1 | Academy Frame 35mm | AF 35mm |
| 1.65:1 1.75:1 1.85:1 | Masked 35mm | Masked 35mm | |
| Panavision Spherical Wide Screen | 1.37:1 | AF 35mm | AF 35mm |
| 1.37:1 1.75:1 1.85:1 | Masked 35mm | Masked 35mm | |
| Techniscope Anamorphic (Panavision 35mm, Todd-AO 35mm, etc) | 2.35:1 2.35:1 | Camera Masked Std width 2 perf high 35mm 35mm | Optical/ Anamorphic 35mm |
| Anamorphic 35mm | |||
| Optical 70mm | |||
| System | Pers per frame print | Optical System | |
|---|---|---|---|
| Camera | Projection | ||
| Standard 16mm | 1 | Std 16mm | Std 16mm |
| Super 16mm | 4 | Std 16mm | Std 35mm |
| Standard 35mm Wide Screen | 4 | Std 35mm | Std 35mm |
| 4 | Std 35mm | Widescreen 35mm | |
| Panavision Spherical | 4 | 35mm Panavision Spherical | Std 35mm |
| Widescreen | 4 | Std 35mm | Widescreen 35mm |
| Techniscope | 4 | Std 35mm | Anamorphic |
| Anamorphic | 4 | Anamorphic | Anamorphic |
| Panavision 35mm, Todd-AO 35mm etc | 5 | Std 70mm | |
System |
Proj. Speed |
Audio |
|||
Frames per Sec. |
Feet per Min. |
Sound
|
No. per
|
Sound to Picture
|
|
| Standard 16 mm |
24 | 36 | Optical | 1 | 26 Ahead |
| Super 16 mm |
24 | 90 | Optical | 1 | 20 Ahead |
|
Standard 35mm Wide Screen |
24 | 90 | Optical | 1 | 20 Ahead |
| 24 | 90 | Optical | 1 | 20 Ahead |
|
|
Panavision Spherical Wide Screen |
24 | 90 | Optical | 1 | 20 Ahead |
| 24 | 90 | Optical | 1 | 20 Ahead | |
|
Techniscope Anamorphic |
24 | 90 | Optical or Magnetic |
1 4 |
20 Ahead 28 Behind |
| 24 | 90 | Optical or Magnetic |
1 4 |
20 Ahead 28 behind |
|
| 24 | 112.4 | Magnetic | 6 | 24 Behind | |
| System | Proj. Speed | Audio | |||
| Frames per Sec. | Feet per Min. | Sound | No. per | Sound to Picture | |
| Track | Tracks | (Frames) | |||
| Standard | 24 | 36 | Optical | 1 | 26 |
| 16 mm | Ahead | ||||
| Super | 24 | 90 | Optical | 1 | 20 |
| 16 mm | Ahead | ||||
| Standard 35mm | 24 | 90 | Optical | 1 | 20 |
| Ahead | |||||
| Wide Screen | 24 | 90 | Optical | 1 | 20 |
| Ahead | |||||
| Panavision Spherical | 24 | 90 | Optical | 1 | 20 |
| Ahead | |||||
| Wide Screen | 24 | 90 | Optical | 1 | 20 Ahead |
| Techniscope | 24 | 90 | Optical or | 1 | 20 |
| Magnetic | 4 | Ahead | |||
| Anamorphic | 28 | ||||
| (Panavision 35mm, Todd-AO 35mm, etc. | Behind | ||||
| 24 | 90 | Optical or | 1 | 20 | |
| Magnetic | 4 | Ahead | |||
| 28 | |||||
| behind | |||||
| 24 | 112.4 | Magnetic | 6 | 24 Behind | |
The following systems are being phased out of production or are already obsolete:
System |
Aspect
|
Guage |
|
Negative |
|
||
| Cinemascope | 2.65:1 | 35mm | Anamorphic 35mm |
| Todd-AO 70 | 2.2:1 | 65mm | 70mm |
| Technirama 70 | 2.2:1 | Double Frame Horizontal 35mm | 70mm |
| Super Panavision | 2.2:1 | 65 mm | 70mm |
| Cinerama Dimension 150 Ultra-Panavision |
2.7:1 | 65mm | 70mm |
System |
Perfs.
|
Optical System |
|
Camera |
Projection |
||
| Cinemascope | 4 (Foxhole type) |
Anamorphic | Anamorphic |
| Todd-AO 70 | 5 | Std 65mm | Std 70mm |
| Technirama 70 | 5 | Anamorphic Technirama | Std 70mm |
| Super Panavision | 5 | Std 65mm | Std 70mm |
| Cinerama Dimension 150 Ultra-Panavision |
5 | Anamorphic | Variable anamorphosis to each side and 120° screen curvature |
System |
Proj. Speed |
Audio |
|||
Frames per Sec. |
Feet per Min. |
Sound
|
No. per
|
Sound to Picture
|
|
| Cinemascope | 24 | 90 | Magnetic | 4 | 28 Behind |
| Todd-AO 70 | 24 | 112.4 | Magnetic | 6 | 24 Behind |
| Technirama 70 | 24 | 112.4 | Magnetic | 6 | 24 Behind |
| Super Panavision | 24 | 112.4 | Magnetic | 6 | 24 Behind |
| Cinerama Dimension 150 Ultra-Panavision |
24 | 112.4 | Magnetic | 6 | 24 Behind |
^^ 1969, The Focal Encyclopedia of Film and Television Techniques, Focal Press, London, New York