Live Meter
Lux or foot-candles with the ± uncertainty band right next to the number. A 60-second rolling chart shows average, minimum and maximum in real time. Optional moving-average or Kalman smoothing.
Light measurement you can trust
Luxwise your light is
Luxwise: Lux & Light Logger (decided 2026-10-05). C# .NET 10 MAUI, iPhone + Android, fully offline, no server. Android reads the real ambient light sensor (SENSOR_DELAY_FASTEST while measuring, foreground service for long logging with the screen off); iOS has no public light-sensor API, so lux is estimated from camera exposure (ISO/shutter/aperture -> EV -> lux) and labelled as a camera estimate; logging on iOS only while open. CCT in Kelvin from the camera white balance (warm/neutral/cool, approximate). Every reading shows a ± error band and a 'not calibrated' warning until calibrated (Lux = raw x m + b, two-point helper, profiles per phone/reference meter). Background C# pipeline (channels, no per-sample allocations), throttled UI, optional smoothing. Free: live lux/fc, chart, avg/min/max, approx CCT, one calibration profile, logging up to 5 minutes, AdMob banner on results/history/settings (never on the live reading). Pro $7.99 once (com.bekservice.luxwise.pro): unlimited/all-day logging, CSV export, guided room-grid survey with U0 = Emin/Eavg + heat map, PDF Inspection Report vs common EN 12464-1 reference values (no certification claim), unlimited calibration profiles, plant mode (PPFD/DLI estimates), no ads. No analytics/tracking SDKs beyond AdMob/UMP.
What it does
Colour Temperature
Colour temperature in kelvin estimated from the camera white balance, labelled warm, neutral or cool. The app marks this as approximate — useful for quick comparisons, not for precision work.
Calibration
Guided one- or two-point calibration beside a reference lux meter. Each profile stores its factor and offset. The active profile name and calibration date appear on every export.
Long Logging
Log at 100 ms, 1 s, 10 s or 1-minute intervals. On Android a foreground service keeps logging with the screen off. Export to CSV with the calibration details in the header. Pro removes the 5-minute limit.
Room Survey
Enter the room dimensions and the app lays out the measurement grid, guides you point by point, then calculates average, minimum, maximum and uniformity U₀ = Emin ÷ Eavg with a heat map. Results are compared with reference values from EN 12464-1 — a guide, not a certification. (Pro)
Plant Mode
Estimates PPFD and daily light integral from your lux reading for six source types: sunlight, white LED, fluorescent, HPS, metal halide and red/blue grow lights. (Pro)
A look inside
Honest about what a phone can and cannot do
iPhone reads from the camera
iPhone has no light sensor available to apps. Luxwise estimates illuminance from the camera's ISO, shutter speed and aperture, and labels every reading as a camera estimate. Lay the phone screen-up at work height and calibrate once beside a reference meter for tighter numbers.
Every reading shows its uncertainty
The ± error band appears next to every reading, not buried in a footnote. The app shows a 'not calibrated' warning until you complete calibration. PDF inspection reports state how readings were taken and how uncertain they are — no certification claims, no fake stamps.
Your data stays on your device
Readings, logs, surveys and reports are stored locally. No account required. Fully offline. No analytics or tracking SDKs. The free version shows AdMob banner ads after you set your consent preference. Pro removes them with a single one-time payment.