Using 120 Film in Zenza Bronica SQ Ai 220 Back: Exploring Compatibility and Film Options

The Zenza Bronica SQ Ai is a beloved medium format camera, renowned for its modular system and sharp lenses. Its film backs, particularly the 220 backs, are designed to take 220 film—a longer roll than 120 film, allowing for more frames per load. However, with 220 film being discontinued and increasingly scarce, photographers often wonder about using 120 film in a 220 back. Here’s what you need to know.

Physically, both 120 and 220 films are the same width and spool size, so it’s possible to load 120 film into a 220 back. The main difference is thickness: 120 film uses a paper backing throughout, whereas 220 film has backing only at the start and end. This means 120 film is thicker when loaded, and the back's film pressure plate isn’t ideally set for it. In practice, many photographers have used 120 film in a 220 back, but you’ll need to be mindful of a few things:

1. Frame Counting: The camera will not stop winding after 12 frames with 120 film in a 220 back—because it’s set to expose up to 24 on 220 film. You must stop winding after 12 frames to avoid exposing blank film.
2. Film Flatness: Since the pressure plate in a 220 back is designed for thinner film (without full backing), using 120 film can sometimes lead to minor focus shifts or less-than-ideal flatness, though many users report the difference is negligible.
3. ISO Tag and Reminder: Remember to adjust the film speed setting to match your 120 film, as you’re adapting a back made for a different film type.
4. Tape the Film End: 120 films have backing paper all the way, so make sure it’s tightly wound and secure to avoid accidental light leaks at the end.

As a designer, I find this type of adaptation fascinating. It’s a creative, resourceful solution to a dwindling resource issue in analog photography. If you want a more streamlined and versatile workflow, or perhaps digitally catalog your film photography setups for future reference, consider using a cloud-based home designer tool to map and organize your camera gear, film stocks, and shooting plans. This visual approach helps you plan better and keeps your creative process organized—much like storyboarding an interior design project.

Tips 1:

If you’re shooting 120 film in a Bronica SQ Ai 220 back, load carefully, keep count of your shots, and check the film tension as you wind. Label your film backs to prevent mistakes in the field. For ultimate peace of mind in sharpness-critical work, you may want to seek out a genuine 120 back when shooting 120 film, but the workaround is reliable for most personal and creative projects.

FAQ

Q: Can I use 120 film in a 220 back on the Bronica SQ Ai?

A: Yes, you can, but you’ll need to manually count exposures and may encounter slight focus issues due to differences in film thickness.

Q: Will the pressure plate cause problems with 120 film?

A: While the difference in pressure plate setting is minor, under certain lighting or wide aperture conditions, some softness may occur.

Q: Do I get 24 shots when using 120 film in a 220 back?

A: No, you only get 12 shots per roll; winding for 24 will result in blank frames as there’s not enough film length.

Q: Is there a risk of light leaks or scratching with this method?

A: If you load with care and ensure the backing paper is secure, the risk is low. Scratching is uncommon but possible if the film isn’t kept taut.

Q: Are there any permanent modifications needed to use 120 film in a 220 back?

A: No permanent modifications are needed; just load the film, keep track of exposures, and develop as usual.