The standard aspect ratio of a photo based on 35mm film is 3:2.
The aspect ratio of an image describes the proportional relationship between its width and its height. It is typically expressed as two numbers separated by a colon (width:height). For photos shot on traditional 35mm film, this ratio has been standardized due to the physical dimensions of the film frame.
Why 3:2 is Standard
The 3:2 aspect ratio originates directly from the standard frame size of 35mm film. The image area on a strip of 35mm film measures approximately 36mm in width by 24mm in height.
- Width: 36mm
- Height: 24mm
When you simplify the ratio of 36:24 by dividing both numbers by 12, you get 3:2. This historical basis is why 3:2 is widely considered the standard aspect ratio for photographs, especially in the context of film photography and digital cameras designed to emulate this standard. As the reference states, "Most photographers choose to shoot in 3:2 aspect ratio... a standard ratio of an image based on 35mm film."
Common Aspect Ratios in Photography
While 3:2 is the historical standard from film, other aspect ratios are commonly used today, often dictated by camera sensors or intended display formats.
Here are a few common ratios:
- 3:2: The traditional standard, rooted in 35mm film dimensions. Offers a classic look and is common on DSLRs and mirrorless cameras.
- 4:3: Often found on Micro Four Thirds cameras and many digital point-and-shoots. This ratio is closer to the screen shape of older televisions and computer monitors.
- 1:1: A perfect square, popularized by platforms like Instagram. Some cameras offer this as an in-camera option.
- 16:9: Wide format, often used for video (like HDTV) or panoramic shots.
The reference specifically mentions 4:5 as an alternative ratio, noting, "But if you're planning to shoot just for social networks purposes, choosing 4:5 in your camera may work in your favor." This highlights how the intended use can influence the chosen aspect ratio, moving beyond the traditional film standard.
| Aspect Ratio | Description | Common Origin/Use |
|---|---|---|
| 3:2 | Wider, less tall | Standard 35mm Film, DSLRs, many Mirrorless |
| 4:3 | Squarer than 3:2 | Micro Four Thirds, Older Digital Cameras, Phone Cameras |
| 1:1 | Square | Social Media (e.g., Instagram Feed) |
| 4:5 | Taller than 3:2 or 4:3 | Social Media (e.g., Instagram Portrait) |
| 16:9 | Much wider, shorter | Video (HDTV), Panoramic Shots |
In summary, while various aspect ratios exist in modern photography, the 3:2 ratio is the direct descendant and standard for photos based on traditional 35mm film.
