LumenLab - Lux Meter

Camera Light Meter · EV

Only for iPhone

Free · In‑App Purchases · Designed for iPhone. Not verified for macOS.

iPhone

LumenLab is a 100% software-only lux meter that uses your iPhone's built-in rear camera — no external hardware, no Bluetooth accessory, no MFi device required. LumenLab turns your iPhone's rear camera into a real-time light meter. By reading the camera's exposure metrics (ISO, shutter, aperture), it computes the illuminance of your environment in lux — perfect for photographers, plant growers, interior designers, and anyone who cares about lighting. KEY FEATURES • Real-time lux reading using camera exposure parameters • Color-coded zones: dark · dim · normal · bright · glaring • Lighting recommendations for each level • One-tap session reset • Fully offline — no network, no tracking, no ads USE CASES • Photographers checking ambient light levels • Cinematographers metering scene illumination • Plant growers ensuring grow-light intensity • Interior designers checking room brightness • Office ergonomics (recommended 300–500 lux) • Reading nook brightness check PRO FEATURES (optional subscription) • Advanced metrics row: EV, ISO, Shutter, Aperture (f/) • Session statistics: minimum, average, maximum lux • Calibration multiplier to align with a professional reference meter • CSV export of full session log (timestamp, lux, EV) • Zero ads forever HOW IT WORKS LumenLab opens the camera (no recording, no preview saved), reads the device's auto-exposure metrics every frame, and applies the photographic equation: EV = log₂(N²/t) − log₂(S/100) lux ≈ 2.5 × 2^EV × calibration This is the same approximation used by entry-level photographic light meters. For absolute accuracy, calibrate against a professional Type-C lux meter. LIMITATIONS The iPhone camera is not a calibrated photometer. Readings are estimates with ±20% typical accuracy without user calibration. Not suitable for regulatory, lab, or safety measurements. PRIVACY The camera is opened only to read auto-exposure metadata. No images, video, or audio are recorded, saved, or transmitted. No analytics, no ads, no account. SUBSCRIPTION INFO • Payment will be charged to your Apple ID account at confirmation of purchase. • Subscription automatically renews unless auto-renew is turned off at least 24 hours before the end of the current period. • Your account will be charged for renewal within 24 hours prior to the end of the current period. • You can manage and cancel your subscriptions by going to App Store → Account → Subscriptions. Privacy Policy: https://frexx.top/lumenlab/privacy.html Terms of Use: https://frexx.top/lumenlab/terms.html SUPPORT 475740640@qq.com

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This update improves camera availability handling and measurement clarity. LumenLab now shows explicit states for camera permission, unsupported devices or simulators, startup failures, and invalid exposure data instead of leaving the reading at 0 lux. The app also explains that lux readings are camera-exposure estimates and should be calibrated against a reference meter for critical work. Real-device camera start, sampling, stop, and repeated start/stop flows were reverified.

Version 1.0.3

The developer, 杰 向, 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

    Accessibility

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

    Information

    Seller
    • 杰 向
    Size
    • 624.6 KB
    Category
    • Photo & Video
    Compatibility
    Requires iOS 15.0 or later.
    • iPhone
      Requires iOS 15.0 or later.
    • iPod touch
      Requires iOS 15.0 or later.
    • Mac
      Requires macOS 12.0 or later and a Mac with Apple M1 chip or later.
    • Apple Vision
      Requires visionOS 1.0 or later.
    Languages
    • Simplified Chinese
    Age Rating
    4+
    In-App Purchases
    Yes
    • LumenLab Pro Weekly $2.99
    • LumenLab Pro Yearly $19.90
    • Learn More
    Copyright
    • © 2026 Clawbot
  • Privacy Policy

    • More by 杰 向

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