35mm half-frame film is the 18x24mm format on regular 35mm film.
Understanding the 35mm Half-Frame Format
The term "half-frame" when referring to 35mm film specifically denotes a negative or slide image size of 18x24mm. This is distinct from the standard or "full" 35mm format used in most still cameras, which measures 24x36mm.
According to information available, the 18x24mm size is actually the normal exposure format utilized in 35mm movie cameras. When this format is used in still cameras designed for 35mm film, those cameras are referred to as half-frame cameras.
Key Characteristics:
- Image Size: 18mm by 24mm.
- Film Type: Uses standard 35mm film.
- Relation to Standard 35mm Still Photography: Roughly half the size of the typical 24x36mm frame.
- Relation to Movie Film: This is the standard frame size for 35mm motion picture film.
This smaller frame size offers a key advantage for still photography: you get approximately double the number of exposures on a standard roll of 35mm film compared to using a full-frame camera. For example, a 36-exposure roll typically yields 72 half-frame shots.
Comparison of Formats:
| Format Type | Image Size (Width x Height) | Typical Use | Frames Per Roll (e.g., 36 exp. roll) |
|---|---|---|---|
| 35mm Half-Frame | 18mm x 24mm | Still Cameras, Movie | ~72 |
| Standard 35mm (Full-Frame) | 24mm x 36mm | Still Cameras | 36 |
Understanding the half-frame format is essential for photographers interested in specific camera models or techniques that leverage this smaller image area.
