Light Meter・Lux Meter vs Illuminance Meter

LUX METER — LIGHT LEVELS IN LUX AND FOOT-CANDLES Lux Meter is a camera-based light meter for illuminance. Aim the rear camera at a surface and read the level in lux and foot-candles, plus EV at ISO 100 — desk lighting, a grow light over houseplants, a scene for an analog camera. WHY THE NUMBER IS WORTH TRUSTING ▸ Metering method always on screen: Reflected · Point AE or Reflected · Center. ▸ Readiness comes from a 1.2-second EV window: 6 valid samples over 650 ms within a 0.16 EV spread to lock, then a 0.28 EV hysteresis against flicker. ▸ No fresh frame for 2 seconds reads Stale; unusable metadata reads Error. ▸ Moving the target, changing zoom or lens, returning from background or recalibrating restarts the window. ▸ Nothing saves or samples until the reading is valid and stable. ROOM AND WORKPLACE LIGHT LEVELS Pick the space or task, then run the five-point survey: five samples across the working plane, each held until stable, giving average, minimum, target range, observed min/average uniformity and the sampling grid. 15 practical targets in 5 groups: general office 300–500 lx, detailed office work 500–750, precision factory 750–1000, warehouse and hospital ward 100–200, corridor 100–150, classroom 300–500, library 500+, operating room 1000+, bedroom 50–150, plus kitchen, bathroom, garage, retail floor and restaurant — practical guidance, never legal certification. GROW LIGHTS, PPFD AND DLI FOR PLANTS Measure at the leaf plane of one plant and decide for that plant: pick the plant, the light source and the photoperiod, and the reading becomes a PPFD and DLI estimate in mol/m²/day. 16 plants carry daily targets: pothos and snake plant 2–4, ZZ plant 1–3, peace lily 3–6, monstera and philodendron 4–8, fern 4–7, rubber plant 5–10, fiddle leaf fig 8–12, plus bird of paradise, succulent, herbs, tomato, pepper, lettuce and strawberry. 5 light sources: sunlight, white LED, fluorescent, HPS, metal halide. The sample log marks periods it did not cover, so a thin number never passes for a full day. EXPOSURE FOR PHOTO AND VIDEO The same reading solves exposure: aperture priority, shutter priority and manual across f/1.0–f/64, 1/8000 s–60 s and ISO 25–12800 in full, ½ or ⅓ stops. Each solution gives the exact result, the nearest setting your gear really has and the residual error in stops — out of range, by how many. Manual shows Over / Matched / Under on a ±3-stop scale, and Cine turns FPS, shutter angle, ISO/EI and ND into an equivalent shutter and f-number. RECORDS AND CSV EXPORT Readings, surveys, DLI estimates, comparisons and monitoring all land in one history list — each with its method, readiness state, calibration and mode inputs. Page the archive, export to CSV. ALSO INSIDE ▸ Lock a reading; switch lux ↔ foot-candles in one tap ▸ Lux reference — 16 environments, 0.1 lx full moon to 130,000 lx direct sun ▸ EV reference — 11 scenes, −6 EV starlight to +18 EV snow ▸ A/B comparison — capture A, move to B, get the EV difference and brightness ratio ▸ Continuous monitoring — min / avg / max trend, real sampling interval, samples and missed samples, markers; background time logs as a gap ▸ Guided calibration — enter a reference value, aim at a uniform surface, wait for stable, apply the offset LIMITS AND PRIVACY A reflected-light estimate from camera exposure metadata — not an incident meter, not a PAR sensor, not a certified laboratory instrument — so it depends on the surface you aim at. The camera only measures light: no photos taken or stored, nothing uploaded, no account, and readings leave your device only in a CSV you export. Free covers the live reading and its readiness state; Pro removes ads and unlocks every workflow. Point, wait for stable, read the number — and stop guessing how much light really reaches that desk or that leaf. Terms of Use: https://zeroplay.io/docs/legal/terms-of-service Privacy Policy: https://zeroplay.io/docs/legal/privacy-policy

PREMIUM — PURCHASE REQUIRED: All features described below are part of Pro and require a purchase: a weekly or yearly auto-renewing subscription, or a one-time lifetime purchase. Point your iPhone camera at any light and read it in seconds: illuminance in lux and foot-candles, color temperature in Kelvin, photographic EV, and PPFD for your plants. One meter, already in your pocket. Most light meter apps do one thing. Pocket Lux Meter is the whole bench: a live illuminance meter you can calibrate against a trusted reference, plus a spectrum view, film-photography exposure tables, grow-light conversion, a room uniformity grid, and PDF/CSV reports you can hand to someone. Readings are honest estimates from your camera — the app tells you so, and calibration keeps them close. WHAT YOU GET • Know in seconds whether your desk hits the 500 lux an office task needs — a live reading with min, max and average that settles as you sweep the room • See any bulb's color temperature in Kelvin, so the "warm white" you just bought actually matches the 2700K lamps already in the ceiling • Walk into a scene with your film camera and leave with a usable exposure — EV turned into ISO, shutter and aperture pairs you can dial straight in • Find out if your monstera is starving: lux converted to PPFD and DLI for the exact light source, matched against ranges for common houseplants from succulents to ZZ plants • Prove a room is evenly lit with the grid uniformity test — measure point by point instead of guessing • Hand a client or facilities team a PDF or CSV report of saved readings, complete with notes, tags and history comparisons PERFECT FOR • Film photographers metering scenes without a handheld exposure meter • Plant owners and growers dialing in LED, HPS, metal halide or fluorescent lights • Facility managers and office planners checking workspace lighting against reference ranges • Anyone comparing bulbs, fixing a dim desk or testing a new lamp WHY NOT JUST BUY A HARDWARE LUX METER? A decent standalone meter costs real money and lives in a drawer. Your phone is already with you. Calibrate this app once against a reference and it stays useful — and it does what a basic lux meter can't: Kelvin readings, exposure tables, PPFD and DLI conversion, uniformity grids and shareable reports. For regulated or safety-critical work, use certified equipment; for everything else, this is the meter you'll actually have on hand. PRIVATE BY DEFAULT Measurements, notes, tags and calibration settings stay in local storage on your device. Camera frames are processed on-device and never saved. No account, no sign-up. PREMIUM (PURCHASE REQUIRED) Pocket Lux Meter requires an active plan. Full access unlocks every tool: the live lux/foot-candle/EV meter, spectrum and color temperature view, photography exposure tables, plant PPFD and DLI mode, grid uniformity, lighting standards, quick test, screen brightness test, smart analysis, history comparison, and CSV/PDF export. Choose a weekly subscription, a yearly subscription, or a lifetime one-time purchase. Localized prices are shown in the app before you pay. Point your camera at the nearest lamp and get your first reading in under ten seconds. Terms of Use: https://leanstudio.asia/terms-of-use Privacy Policy: https://leanstudio.asia/privacy-policy Support: support@leanstudio.asia