Pretty good overall
If it is possible, adding the adjustment for shutter speed instead of only the aperture will be so much helpful.
$0.99
About
Calculate photographic exposure and development adjustments using zone system theory. Measure shadows and highlights, input film ISO and desired shutter speed to determine aperture and development time modifications.
✓Zone system exposure calculation
✓Shadow and highlight measurement
✓Film ISO input
✓Shutter speed adjustment
✓Development time calculation
✓Aperture determination
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What's New in Zone Tool
1.2
March 3, 2026
Bugfixes
User reviews
Developer apps
FAQ
What is Zone Tool used for?
Zone Tool is used to calculate photographic exposure and development adjustments based on the zone system theory. It helps photographers determine the correct aperture and development time for their film.
How does Zone Tool work?
You input your desired shadow and highlight zones, measure them with your film's ISO, and set your intended shutter speed. The app then calculates the necessary aperture and tells you if development time needs to be shortened or expanded.
Does Zone Tool require a specific type of light meter?
While best results are achieved with a spot light meter, the app suggests that mobile apps should also work adequately for measurements.
What is the price of Zone Tool?
Zone Tool is a paid application, available for $0.99.
On which devices can I use Zone Tool?
Zone Tool is supported on iPhone and iPod devices.
How often is Zone Tool updated?
The latest version, 1.2, was released on March 3, 2026, indicating a potential update schedule, though the last update was in 2019.
What is the age rating for Zone Tool?
Zone Tool has an age rating of 4+, making it suitable for a wide range of users.
Does Zone Tool have ads?
No, Zone Tool does not contain advertisements.