TimerGlass
Reciprocity Failure Calculator
$7.99 · Designed for iPad. Not verified for macOS.
Long exposures after dark, now with a darkroom-inspired Dark Mode. Calculate, expose, and follow the countdown right from your Lock Screen.
TimerGlass is the field companion for film photographers — reciprocity, pinhole geometry, exposure estimation, and a beautiful timer, all in one quietly designed app.
WHAT IT DOES
• Reciprocity failure correction for 100+ film stocks (Ilford, Kodak, Fuji, Foma, Rollei, ADOX, CineStill, Lomography and more) — built from manufacturer data sheets.
• ND filter stack and bellows extension compensation are folded into the same calculation.
• Pinhole camera tool — Lord Rayleigh's optimal aperture, effective f-number, equivalent angle of view by film format, and Sunny-16 exposure estimation that flows straight into the timer.
• Long-exposure timer with Live Activity and Dynamic Island, accurate even when your phone is locked.
• Long-exposure side-effects advice — pull-development guidance for B&W, color-shift tips for negative and slide film, contextual to your actual exposure time.
• History of recent exposures with all the parameters you used.
• Custom film stocks — define your own with power-law or lookup-table reciprocity curves.
DESIGNED FOR
Large-format and pinhole photographers who do long exposures often, 35mm and medium-format shooters chasing dusk and night scenes, and anyone tired of squinting at a film data sheet by torchlight.
LANGUAGES
English, 简体中文, 繁體中文, 日本語, Deutsch, Français.
PRIVACY
TimerGlass collects nothing. Everything you do stays on your device.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
NEW: Dark Mode
• A warm, darkroom-inspired palette that's easy on the eyes at night
• Choose System, Light, or Dark in Settings — takes effect instantly
• The Lock Screen timer card adapts automatically
Works with MeterGlass
• Jump to MeterGlass from the Calculator to meter a scene — your film's ISO comes along automatically
• The measured shutter time returns straight to the Calculator, snapped to the nearest stop
Standalone Timer
• Set a duration right on the Timer tab — no need to go through the Calculator
Better Custom Films
• Lookup-table films now accept your own data points, so corrections match your film's measured behavior
The developer, 存滨 崔, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- 存滨 崔
- Size
- 3.9 MB
- Category
- Photo & Video
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - iPad
Requires iPadOS 17.0 or later. - Mac
Requires macOS 14.0 or later and a Mac with Apple M1 chip or later.
- iPhone
- Languages
English and 5 more
- English, French, German, Japanese, Simplified Chinese, Traditional Chinese
- Age Rating
4+
- 4+
- Copyright
- © 2026 TimerGlass

