# Light Meter LM vs Luminosys

The clearest difference is in-app purchases: Luminosys at none against Light Meter LM's 3. Luminosys also leads on review sentiment (75% vs 40%). Light Meter LM's advantage is ads (none vs shown) and update cadence (monthly vs every 19 months). On price and iOS requirement there is nothing between them.

Both are free to download. Light Meter LM sells 3 in-app purchases, starting at $3.49 per month. Luminosys asks for nothing beyond the download.

Light Meter LM holds the better App Store score, 4.5 against 4.3. That said, the two scores are not equally well evidenced: Light Meter LM has 2.6K ratings behind it against 10, so its average is the more settled of the two. Written reviews complicate that: 40% of Light Meter LM's written reviews are positive against 75% of Luminosys's, so the app with the better star average is not the one people write more warmly about.

Light Meter LM ships an update monthly, Luminosys every 19 months. The most recent releases landed on November 3, 2026 and November 4, 2026 respectively.

## The numbers

| Metric | Light Meter LM | Luminosys |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.5 (2.6K ratings)](https://appshunter.io/ios/app/light-meter-lm-3000/id1554264761/reviews)** | [4.3 (10 ratings)](https://appshunter.io/ios/app/luminosys-light-meter/id6476405389/reviews) |
| Number of ratings | **2.6K** | 10 |
| Positive reviews | 40.4% of reviews | **75.0% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | **No** | Yes |
| Update frequency | **Monthly** | Every 19 months |
| Monetization | Free with in-app purchases | **Ad-supported** |
| Size | 22 MB | 3 MB |
| Requires iOS | **15.0** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Lightray Innovation GmbH](https://appshunter.io/developer/1031383431) | [Melissa Zwick](https://appshunter.io/developer/1616726350) |

## What reviewers say

### Light Meter LM

[App page](https://appshunter.io/ios/app/light-meter-lm-3000/id1554264761)

Transform your smartphone into a professional light meter. Measure illuminance and color temperature with scientifically validated accuracy, trusted by professionals. Requires a simple diffuser for precise readings.

**Highlights:** Measure illuminance (lux/foot-candle), Measure color temperature (Kelvin), Industry-leading accuracy, Pre-calibrated for your device, Low light sensitivity, Save peak reading, Custom calibration option

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Continuous Charging | $3.49 | per month |
| Single Charge | $0.99 | one-time |
| Unlimited Battery | $19.99 | one-time |

**What reviewers like**

- 👍 Great app
- 👍 Accurate measurements
- 👍 Easy to use
- 👍 Helpful customer service
- 👍 Useful for science/research

**What reviewers complain about**

- 🐛 Requires diffuser for accurate readings
- 💰 Expensive for a light meter app
- 🔋 Battery/trial period issues
- 🔍 Inconsistent/inaccurate readings
- 🙄 Misleading/deceptive marketing

**Reported bugs**

- Diffuser not recognized even when used
- App locks up/crashes
- Constant diffuser pop-up interruptions

**Requested features**

- Ability to use rear camera
- More flexible diffuser options
- Improved accuracy without diffuser


### Luminosys

[App page](https://appshunter.io/ios/app/luminosys-light-meter/id6476405389)

Accurately measure ambient light levels in Lux or Foot Candles using your phone's camera. This tool is ideal for photography, comparing light sources, or indoor gardening. It's designed for ease of use and provides precise readings.

**Highlights:** Measures light in Lux, Measures light in Foot Candles (FC), Uses phone camera for accuracy, Easy to use interface, Suitable for photography, Useful for indoor gardening

**In-app purchases:** none


## Frequently asked questions

### Is Light Meter LM free?

Light Meter LM is free to download, with in-app purchases available.

### Is Luminosys free?

Luminosys is free to download, with no in-app purchases.

### Which has better reviews, Light Meter LM or Luminosys?

Light Meter LM is rated higher. Light Meter LM averages 4.5 out of 5 from 2.6K ratings, while Luminosys averages 4.3 from 10 ratings.

### Do Light Meter LM or Luminosys have ads?

Luminosys shows ads; Light Meter LM does not.

### Which is updated more often, Light Meter LM or Luminosys?

Light Meter LM ships an update monthly, and Luminosys every 19 months. Most recently, Light Meter LM was updated on November 3, 2026 and Luminosys on November 4, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*