Light Meter - Lux & EV Gauge
Illuminance & Color Temp Tool
$1.99 · Designed for iPad. Not verified for macOS.
Turn your iPhone into a professional light meter. Measure illuminance in lux or foot-candles, exposure value (EV), and color temperature (CCT in Kelvin) — all in real time using your camera.
Whether you're a photographer dialing in the perfect exposure, a plant parent ensuring your houseplants get enough light, or a lighting professional checking workspace compliance, this app delivers the readings you need — no expensive hardware required.
REAL-TIME MEASUREMENTS
• Lux and foot-candle readings updated every frame
• Exposure Value (EV) displayed alongside illuminance
• Correlated Color Temperature (CCT) in Kelvin
• Min, max, and average statistics tracked automatically
PROFESSIONAL ANALOG & DIGITAL DISPLAY
• Beautiful analog gauge with animated needle and gradient arc
• Peak reading marker highlights the maximum value on the gauge
• Large digital display with threshold status indicator
• Switch between analog, digital, or combined view
HOLD & THRESHOLD ALERTS
• HOLD button freezes the current reading instantly
• Set a target lux range and get haptic feedback when readings cross your threshold
• Visual indicators show whether you're below, within, or above your target
LIVE GRAPH
• Rolling real-time chart shows light intensity trends
• Spot changes in lighting conditions at a glance
RECORD & SHARE
• Record measurement sessions with one tap
• Sessions save min, max, average lux, duration, and reading count
• Export and share session reports via text — perfect for documentation
CAMERA FEATURES
• Works with front and rear cameras
• Built-in flashlight toggle for additional illumination
• Live camera preview with overlay controls
CALIBRATION & SETTINGS
• Adjustable calibration multiplier for consistent readings
• Customizable analog gauge scale
• Choose your preferred unit: lux or foot-candles
• Keep Screen On option for extended measurements
• Dark-optimized interface for comfortable use
HOW IT WORKS
The app analyzes live video frames using Core Image to compute average scene brightness, then applies an EV-based formula accounting for exposure duration, ISO, and aperture. Color temperature is estimated from RGB chromaticity using McCamy's approximation. A calibration multiplier lets you align readings with a reference meter for improved accuracy.
Note: Smartphone cameras approximate light levels and are not a replacement for certified laboratory instruments. Results are relative and best used for comparison, trending, and general-purpose measurement.
PERFECT FOR
• Photographers adjusting studio or natural lighting
• Plant enthusiasts measuring grow light intensity
• Interior designers evaluating room illumination
• Workplace safety and ergonomic lighting checks
• Educators and students studying optics and photometry
• Anyone curious about the light around them
No ads. No subscriptions. Just a powerful, beautifully designed light meter in your pocket.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
The developer, Vladislav Zhirnov, 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
- Vladislav Zhirnov
- Size
- 8.2 MB
- Category
- Photo & Video
- Compatibility
Requires iOS 17.6 or later.
- iPhone
Requires iOS 17.6 or later. - iPad
Requires iPadOS 17.6 or later. - Mac
Requires macOS 14.6 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.3 or later.
- iPhone
- Languages
English and 31 more
- English, Arabic, Croatian, Czech, Danish, Dutch, Finnish, French, German, Greek, Hebrew, Hindi, Hungarian, Indonesian, Italian, Japanese, Korean, Malay, Norwegian Bokmål, Polish, Portuguese, Romanian, Russian, Simplified Chinese, Slovak, Spanish, Swedish, Thai, Traditional Chinese, Turkish, Ukrainian, Vietnamese
- Age Rating
4+
- 4+
- Copyright
- © zhirnov.zsystems
