# LumenLab - Lux Meter — Camera Light Meter · EV

> Camera Light Meter · EV (iPhone/iPad app by 杰 向.)

- Source: https://appshunter.io/ios/app/lumenlab-lux-meter/id6762075216 (this page in markdown: same URL + `.md`)
- Developer: [杰 向](https://appshunter.io/developer/1860305678)
- Category: Photo & Video, Utilities
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 15.0 · 1 MB
- Languages: English, Chinese
- Released: 2026-04-17
- Data updated: 2026-06-26
- User reviews in markdown: https://appshunter.io/ios/app/lumenlab-lux-meter/id6762075216/reviews.md

## What is LumenLab?

LumenLab is 100% software, using your iPhone's built-in camera — no external hardware required. LumenLab turns your iPhone's rear camera into a real-time light meter. By reading the camera's exposure metrics (ISO, shutter, aperture), it computes the illuminance of your environment in lux — perfect for photographers, plant growers, interior designers, and anyone who cares about lighting.

KEY FEATURES
• Real-time lux reading using camera exposure parameters
• Color-coded zones: dark · dim · normal · bright · glaring
• Lighting recommendations for each level
• One-tap session reset
• Core measurement works offline — no tracking, no ads, no account

USE CASES
• Photographers checking ambient light levels
• Cinematographers metering scene illumination
• Plant growers ensuring grow-light intensity
• Interior designers checking room brightness
• Office ergonomics (recommended 300–500 lux)
• Reading nook brightness check

PRO FEATURES (optional subscription)
• Advanced metrics row: EV, ISO, Shutter, Aperture (f/)
• Session statistics: minimum, average, maximum lux
• Calibration multiplier to align with a professional reference meter
• CSV export of full session log (timestamp, lux, EV, calibration factor)
• Zero ads forever

HOW IT WORKS
LumenLab opens the camera (no recording, no preview saved), reads the device's auto-exposure metrics every frame, and applies the photographic equation:

  EV = log₂(N²/t) − log₂(S/100)
  lux ≈ 2.5 × 2^EV × calibration

This is a practical camera-exposure estimate. For critical comparisons, calibrate against a known light source or reference meter.

LIMITATIONS
The iPhone camera is not a calibrated photometer. Readings are estimates and can vary by device, lens, scene reflectance, and auto-exposure behavior. Not suitable for regulatory, lab, or safety measurements.

PRIVACY
The camera is opened only to read auto-exposure metadata. No images, video, or audio are recorded, saved, or transmitted. No analytics, no ads, no account. StoreKit is used only for the optional Pro subscription.


SUBSCRIPTION INFO
• Payment will be charged to your Apple ID account at confirmation of purchase.
• Subscription automatically renews unless auto-renew is turned off at least 24 hours before the end of the current period.
• Your account will be charged for renewal within 24 hours prior to the end of the current period.
• You can manage and cancel your subscriptions by going to App Store → Account → Subscriptions.

Privacy Policy: https://frexx.top/lumenlab/privacy.html
Terms of Use: https://frexx.top/lumenlab/terms.html

SUPPORT
jie.xiang.jm@gmail.com

## Pricing and in-app purchases

Base price: Free.

**Subscriptions**

| Subscription | Price | Period |
| --- | --- | --- |
| LumenLab Pro Yearly | $19.90 | per year |
| LumenLab Pro Weekly | $2.99 | per 7 days |



## Version history (last 4 releases)

### 1.0.5 — 2026-06-20

LumenLab now adds Room Fit guidance, turning the lux reading into clearer advice for reading, desk work, detail tasks, bright spaces, and glare risk. The top controls also have larger tap targets, and the simulator camera fallback, Pro export, and calibration flow were rechecked for this release.

### 1.0.2 — 2026-05-12

Improves review readiness, localization, privacy details, and stability based on the latest validation pass.

### 1.0.1 — 2026-04-18

Description clarified — software-only, no external hardware required.

### 1.0 — 2026-04-17

No release notes.

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All apps by 杰 向: https://appshunter.io/developer/1860305678

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-26.*