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.

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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.

    Privacy practices may vary, for example, based on the features you use or your age. Learn More

    The developer has not yet indicated which accessibility features this app supports. Learn More

    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.
    Languages
    English and 5 more
    • English, French, German, Japanese, Simplified Chinese, Traditional Chinese
    Age Rating
    4+
    Copyright
    • © 2026 TimerGlass