Luminosys vs Lux Meter

Luminosys allows you to accurately measure the ambient light level in Lux or Foot Candles (FC). To do this, Luminosys uses your phone's camera in conjunction with a piece of paper to accurately measure the light level. It is very easy to use and is a great app for those looking for accurate light measurements for photography, comparing light sources, or indoor gardening.

Lux Meter turns your iPhone into a professional light meter. Using your camera and the ISO 2720 photographic standard, it measures illuminance in lux and foot-candles in real time — accurately, fully offline, with no ads and no sign-up. Whether you're setting up studio lighting, checking your desk for eye comfort, dialing in grow lights for plants, or metering a film scene, Lux Meter gives you the numbers the pros rely on. MEASURE • Real-time lux and foot-candle readout (tap to switch units) • Exposure Value (EV) at your chosen ISO • Color temperature (CCT in Kelvin) estimate from the camera • Live camera preview with a center spot reticle • Spot metering (center) or average metering (whole frame) • Min / max / average statistics with a live chart • Hold to lock a reading • Plain-language light labels (Office lighting, Overcast day, Direct sunlight…) • Low-light path reads down to sub-1 lux EXPOSURE CALCULATOR (2-in-1) • Set any two of aperture / shutter / ISO — it solves the third • Cinema mode: frame-rate and shutter-angle presets, plus the 180° rule • ND filter and exposure compensation • Sunny 16 helper and a depth-of-field estimate TARGETS & PRESETS • Use-case presets: Reading, Office/Ergonomics, Photography, Film/Video, Plants & Greenhouse, Aquarium/Terrarium • Set a target lux band and get a subtle alert when the light is in range • Optional haptic and audio meter tick that speeds up as light increases CALIBRATION YOU CAN TRUST • Independent calibration for front and back cameras • Multi-point calibration fitted across the whole range • See raw and calibrated values side by side • Reset to default anytime SAVE & EXPORT • Save single readings or record a session over time • Min/max/average per session, notes and optional location tag • History list with rename, delete and CSV export (share sheet) BUILT RIGHT • Works 100% offline — no account, no tracking, no network • No ads, nothing locked behind a paywall • Grid and histogram overlays, screen-brightness pin, keep-awake • Clean dark-first design, light mode too • 8 languages with instant in-app switching A note on accuracy: iOS does not give apps access to the ambient light sensor, so Lux Meter uses camera-based reflective metering (ISO 2720). For best results, calibrate once against a reference and use the same lighting conditions. Measure light like a pro. Download Lux Meter.