Factor: Precision Light Meter
Light Meter & Exposure Tools
Archived App (Last seen on 3 Jul 2025)
This is an archived listing of the app previously available on the App Store.Although the app is no longer distributed by Apple, you can still view its description, screenshots, version history, ratings, and metadata for reference.
Lowest price: Free 3 years ago (-100%)
Price history
About
Transform your iPhone into a professional light meter for film and digital photography. Calculate precise shutter speeds, exposure compensation for filters, and manage long exposures with reciprocity failure compensation. Ideal for manual shooters and large format artists.
What's New in Factor
3.2.3
June 25, 2025
Updated app icon set that now supports customization
Developer apps
FAQ
What is Factor?
Factor is a precision light meter app that turns your iPhone into a professional tool for photographers. It offers features like a reflected light meter, filter factor calculator, bellows extension calculator, and reciprocity failure calculator.
How much does Factor cost?
Factor is a paid app, priced at $0.99. This one-time purchase grants you access to all its features without any subscriptions or in-app purchases.
What devices does Factor support?
Factor is currently supported on iPhone devices. It is designed to leverage the camera and processing capabilities of iPhones for its light metering functions.
Is Factor suitable for beginners?
While Factor offers professional-grade tools, its precision features are particularly beneficial for experienced film photographers, large format artists, and manual digital shooters. Beginners might find the advanced calculations require some understanding of photographic principles.
Does Factor have ads?
No, Factor does not contain advertisements. As a paid application, it provides an ad-free experience for its users.
How often is Factor updated?
Factor was last updated on June 25, 2025, indicating active development and support. Users can expect ongoing improvements and potential new features.
What is the age rating for Factor?
Factor has an age rating of 4+, making it suitable for users of all ages. This rating reflects the app's content and functionality.
Can Factor help with long exposures on film?
Yes, Factor includes a Reciprocity Failure Calculator specifically designed to help with long exposures on film. You can manage a library of your film stocks' unique characteristics to get precisely adjusted exposure times.
