Light Meter LM-3000 4+

Simple & accurate measurement‪!‬

Lightray Innovation GmbH

Designed for iPad

    • 4.6 • 1.7K Ratings
    • Free
    • Offers In-App Purchases



Measure illuminance in lux or foot-candle with the most accurate light meter app out there.

Why waste money on a hardware meter when you’re already carrying one in your pocket?
The LM-3000 offers the same quality and usability as a handheld or pocket light meter. You won't need any additional light sensor — the camera already got you covered. The LM-3000 comes with a clean and simple user interface and most importantly: No Ads!

See it in action here:

The LM-3000 is even more accurate than almost any cheap light meter available. Besides that, its measurement algorithm delivers unrivaled sensitivity to capture the faintest lighting changes, empowering new possibilities in light pollution and health research.

Developed and tested by optics scientists and engineers, calibrated using professional grade Class A equipment for all iPhones and iPads, the LM-3000 is truly a light meter you can trust!

Download the app for free and use it for some time! If you like it, you may buy the unlimited battery pack to use the LM-3000 for as long as you want, even when switching to a new device. Your purchase allows us to provide an Ad-free experience and helps our small team to keep on building great apps to measure light accurately and easily.

If you encounter any problems or have feedback, don't hesitate to reach out:

As a proud member of 1% for the Planet we are donating at least one percent of all our revenue to environmental nonprofit organizations. With everything that you purchase from us, YOU will be giving back!

What’s New

Version 1.9.2

We've added factory calibrations for the latest iPhone 15, 15 Plus, 15 Pro, and 15 Pro Max to ensure you get the highest accuracy available on any smartphone out there.

Ratings and Reviews

4.6 out of 5
1.7K Ratings

1.7K Ratings

Arizona_Lion ,

Well done

I don’t go out of my way to write reviews for apps, but this was so handy for me today. I used it to quantify what portions of the building I do maintenance for “feels dark” I was able to pinpoint mismatched/incorrect/burnt out bulbs and now I’m noticing that many of my illuminated LED down lights are past their prime and no longer giving off adequate light.

Very reasonable amount of use for the free trial and the “battery life” on the meter indicating how many uses are left is a nice touch.

Included video link and supporting documents are excellent and very handy. Went ahead and purchased the full battery knowing I will certainly put this app to use again in the coming weeks. Seriously well done on this 👍🏾

Developer Response ,

Hi Arizona_Lion,
Thank you very much for your insightful review! We're very happy to hear that our app is so helpful to you :)
Best regards,
Dominik and the Lightray Team

KJPA77 ,

This is a scam

Free? When I first opened it I was required to make a light diffuser. Hmm okay. Easy enough. Once I got that attached to my iPhone the app popped up saying the meter ran out of battery and it would be $7.99 to purchase a lifetime battery. No options. My phone battery is 100% so that’s not the problem. This thing actually costs $7.99 if you want to use it. I wouldn’t be surprised if it continues to demand future purchases of something or other in order to use it. BTW, I have no idea if the light meter works. I never got that far.
Update after developer’s response: I’m not confused about it being my phone battery. I’m confused how Apple lets you act like this is a free app but it’s only free to download, not free to use. It should be sold as an app for $7.99. It might even be worth it. But I’ll never know because I won’t trust a developer that says the app is free when it’s not.
Update again after developer reply that this is a “try before you buy” app. No, it’s not. I didn’t get to try it. First it told me I needed the filter. So I made that. Then when I tried to use it, I got the message that the battery was empty and I needed to pay $7.99 for the lifetime battery. I never saw any light measurement at all. Why would I pay for this? You guys need to try using this from a phone not registered to one of you and see how it really works. Edit: I’m a systems analyst, software tester, support team member so I have some experience in this realm.

Developer Response ,

Hi KJPA77,

Thank you for reaching out with your feedback. 

It seems like the hypothetical battery of our light meter resulted in some confusion: It has nothing to do with your phone's battery. As the intention of our app is to replace a dedicated (and costly!) handheld light meter, you also won't need to purchase anything else in our app and the "battery" is valid a lifetime as long as you use the same Apple ID. Please feel free to reach out to our support if you need help to get it to work.

As you can imagine, developing an app requires a lot of time, effort, and money. To compensate for this there are basically two options: Show you tons of ads and thus also "sell your data" OR offer a paid or freemium app...that's why we've chosen the latter. 

BTW, it works very well. You can find more information about the accuracy on our website.

Best regards,
Dominik and the Lightray Team

Updated response:

Hi KJPA77,
I understand and we could consider making it a paid app right away. However, we've chosen this approach to offer a "try before you buy" option so users can get a sense of our product before having to buy it. More information about this trial can also be found in our app's description.
Best regards,
Dominik and the Lightray Team

约礼 ,

Absolutely Amazing

Most serious app I’ve ever seen although I’m a little bit doubtful about using camera to measure the accurate brightness since most camera have auto brightness and exposure control. It even requires a diffuser (don’t worry, just put a piece of paper on your front cam), which is quite professional unlike other app. Absolutely like it, thanks!

It is a very smart way to tell people the trial is over using a battery lol, love it and will buy it later

Developer Response ,

Hi 约礼,
Thank you so much for that review ❣️
And don't worry about the camera... LM-3000 will configure and use it in such a way that it exactly meets its purpose of being an accurate light meter. We've put a lot of effort in this behind the curtain 🤓.

Best regards,
Dennis & the Lightray Team

App Privacy

The developer, Lightray Innovation GmbH, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Not Linked to You

The following data may be collected but it is not linked to your identity:

  • Diagnostics

Privacy practices may vary, for example, based on the features you use or your age. Learn More

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