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Filmmaking Dictionary: Number 1 / 1.33:1 (4:3 Aspect Ratio)
Definition
4:3 is an image shape four units wide for every three units high. Dividing four by three gives 1.333…, so the same shape is commonly described as 1.33:1. It is associated with early motion-picture framing and traditional television.
Aspect ratio describes the picture’s shape. It does not identify its resolution, film gauge, frame rate or image quality. A digital production can use 4:3 deliberately without imitating an old television recording.
4:3 Is Not Quite Academy Ratio
The approximately 1.37:1 Academy Ratio used for 35mm sound-film presentation is slightly wider than 4:3. The difference is small enough to be overlooked on a casual viewing, but it matters when setting frame lines, restoring a film or preserving an original composition.
Do not assume every older film should be cropped to 4:3. Establish the intended picture area for the specific material. A transfer, broadcast version or online upload may already contain a crop or added borders.
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Composing Within the Frame
Compared with 16:9 at the same picture height, 4:3 provides less horizontal room. Two people positioned far apart may require different blocking, a wider camera position or a tighter emphasis on one person. Vertical relationships and a face’s placement within the frame become especially noticeable.
An interview can use the format to keep attention close to the subject, but that is a creative choice rather than a property guaranteed by the ratio. Lens choice, distance, production design and lighting still establish the image’s character.
Delivery to a Wider Screen
- Pillarboxing: Preserve the whole 4:3 picture with unused space at the sides of a wider frame.
- Cropping: Remove picture from the top and bottom to fill a wider display.
- Stretching: Distort the image’s proportions; this is usually an incorrect interpretation.
- Reframing: Choose a deliberate crop for each shot when an alternate version is required.
With square pixels, 1440 × 1080 is a 4:3 raster. However, some historical video formats store non-square pixels, so the stored dimensions alone may not identify the displayed aspect ratio.
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Frequently Asked Questions
Is all 1440 × 1080 video 4:3?
No. Pixel aspect ratio also matters. Some HD formats use a 1440 × 1080 raster intended to display as 16:9.
Can modern films use 4:3?
Yes. Use the intended frame lines during production and communicate the framing to post-production and the exhibitor.
Related Terms
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