# LightScope: Light & EV Meter

> Lux, EV & Film Exposure Meter

Canonical page: [https://chrome-stats.com/d/id1572227924](https://chrome-stats.com/d/id1572227924)

## Overview

- **ID:** `id1572227924`
- **Platform:** Apple
- **Type:** Apple app
- **Status:** Available
- **Publisher:** Byungil Park
- **Category:** Photo & Video
- **Version:** 3.3
- **Last updated:** 2026-09-07
- **First published:** 2021-06-30
- **Size:** 2.25 MB
- **Data as of:** 2026-09-19
- **Store listing:** [Apple App Store](https://apps.apple.com/us/app/lightscope-light-ev-meter/id1572227924)
- **Website:** [http://practical.kr](http://practical.kr/)
- **Privacy policy:** [http://practical.kr](http://practical.kr/)

## Description

The measuring screen is new: Instrument mode reads all six values at once, Viewfinder mode meters exactly where you aim. Grow light PPFD and DLI are here too.

LightScope is a comprehensive solution providing professional light measurement and analysis using your iOS device's camera sensor.

【Key Measurement Features】
• Illuminance (lux) Measurement: Calculates accurate illuminance by analyzing EXIF data from the camera sensor. Illuminance is derived using the formula: (F-number² / (Exposure Time × ISO)) × Calibration Factor.
• Exposure (EV) Calculator: Converts measured illuminance to EV and suggests proper exposure combinations in standard stops for your ISO and aperture (or shutter) settings.
• Luminous Intensity (candela) Calculation: Automatically calculates the luminous intensity of a light source based on the set distance. Uses the formula: Illuminance (lux) × Distance².
• Color Temperature (K) & Tint Analysis: Precisely measures the light source's color temperature (1500K~15000K) and tint (green-magenta bias) by analyzing the camera's white balance sensor data — useful for identifying fluorescent and LED lighting.
• Real-time Histogram: Visualizes the balance of shadows, midtones, and highlights through 16-level brightness distribution analysis.
• Contrast Ratio Measurement: Evaluates the brightness ratio between bright and dark areas of a scene (based on 10th/90th percentiles) according to WCAG accessibility standards.
• Noise Measurement (SNR): Calculates the signal-to-noise ratio in dB to evaluate image quality in the shooting environment.

【Advanced Features】
• Image Capture and Storage: Captures camera images at the time of measurement and stores them with measurement data.
• Full-screen Image View: Zoom, pan, and rotate captured images for detailed inspection.
• Gallery Saving: Save captured images to your device's photo library.
• Measurement History and Trends: Save all measurements chronologically and chart trends for lux, EV, color temperature, contrast, and SNR.
• Continuous Logging: Automatically record measurements at a set interval (1-60s) — great for lighting design and site surveys.
• Full-Resolution Image Storage: Keep captured images at original quality for detailed inspection and gallery saving.
• Export All History: Export every measurement as a CSV file or a PDF report.
• Notes & Location Tags: Attach notes to measurements and optionally save the measurement location.
• Home Screen Widget: See your last measurement (lux, color temperature, contrast, SNR) right on the home screen.
• Camera Full-screen Mode: Hide panels to focus on the camera view while checking key measurements via a mini info panel.
• Measurement Lock: Freeze exposure and white balance for stable, steady readings.
• Spot Metering: In full-screen mode, tap anywhere to meter around that point.
• Perfect Dark/Light Mode Support: All UI elements automatically adapt to the system theme.

【User Settings】
• Calibration Wizard: Enter a reading from a reference lux meter and the calibration factor is calculated automatically. Manual slider adjustment is also available.
• Distance Setting: Set the distance to the light source for precise luminous intensity (cd) calculations.
• Front/Rear Camera Selection: Choose the appropriate camera for your measurement situation.

【Technical Features】
• Support for measuring various light source types: natural light, LED, fluorescent, incandescent, etc.
• Color temperature and tint sourced directly from the camera ISP's white balance estimation for reliable readings
• 10-frame moving average filter for measurement stabilization
• Center-weighted or spot (tap-to-meter) analysis for accurate evaluation of the main subject
• Automatic exposure quality assessment based on histogram analysis

Perfect tool for photographers, videographers, lighting designers, UI/UX developers, and anyone who needs accurate light measurements.

## Rankings

- #1,078,551 — Overall

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Source: [Chrome-Stats](https://chrome-stats.com/d/id1572227924)