Lux Light Meter - Luminance

About this app

Lux Light Meter turns your iPhone into a precise illuminance meter with four purpose-built modes — and now keeps a full history of every reading you take. FOUR MODES • Auto — radial gauge with closest reference shown live. • Outdoor — focused 0.001 to 100,000 lx with moonless night, twilight, overcast, full daylight, direct sun references. • Indoor — focused 10 to 10,000 lx with corridor, living room, kitchen, office, reading desk, drafting, surgical references. • Photo — EV @ ISO 100 readout plus suggested shutter speed at f/2.8. WHAT'S NEW • Measurement History — every reading is auto-saved with a 7-day trend chart and insights like "+12% vs your 7-day average". • Notes & Favorites — add a note ("kitchen window 3pm") and star to any saved reading. • Compare Mode — pick two saved readings and view the difference side by side. • Calibration Offset — fine-tune your sensor in ±1 lx steps. • Share Result — share your current lux as an image. • CSV Export — share all your measurements as CSV for spreadsheets. CORE FEATURES • Precise ambient light measurement (lux) • Kalman-smoothed sensor readings • Min/Max/Avg tracking with elapsed time • Log-scale range bar in Outdoor and Indoor modes • EV exposure value for photographers • Microphone calibration FOR PHOTOGRAPHERS · INDOOR GARDENERS · ELECTRICIANS · STUDIO ENGINEERS · OFFICE ERGONOMICS · INDUSTRIAL DIAGNOSTICS Available in 14 languages.

Ads no longer interrupt you mid-task. Anything full-screen now waits until you have finished what you were doing, and the app stops showing a blank pause where an ad failed to load.

Momentum comes from crawler snapshots for the tracked storefront. “Viral growth signal” means unusually fast recent rating gains; it is an indicator, not download data.

1. First observed Aug 18, 2026 · 2:57 AM Free