Light Meter LM-3000

Name: Light Meter LM-3000
Rating: 4.5 (2362 reviews)
Author: Lightray Innovation GmbH

Simple & accurate measurement!

Free · In‑App Purchases · Designed for iPad

2.4K Ratings
Ages

4+
Years
Category

Utilities
Developer

Lightray Innovation GmbH
Language

EN
+ 7 More
Size

22.6
MB

Turn your smartphone into a professional-grade light meter. Measure illuminance (lux/foot-candle) and color temperature (CCT in Kelvin) with unmatched accuracy — trusted by photographers, engineers, and lighting professionals worldwide. 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 traditional hardware light meter. Developed by optics scientists at the Zurich University of Applied Sciences, LM-3000 is the only light meter app scientifically validated for accuracy. It achieves professional-grade precision by leveraging your iPhone's front-facing camera sensor with advanced RAW image processing. Unlike relying on estimates like other apps, it adheres to the ISO/CIE 19476 standard, ensuring measurements you can trust for critical applications. MEASUREMENTS ⎷ Illuminance in lux or foot-candles ⎷ Correlated color temperature in kelvin FEATURES ⎷ Industry-leading accuracy, matching professional high-end lux meters ⎷ Pre-calibrated for your specific device ⎷ Excellent low light sensitivity to detect light pollution ⎷ No ads ⎷ In-app manual ⎷ Save peak reading ⎷ HOLD function with acoustic signal ⎷ Custom calibration option to align readings to another meter DIFFUSER REQUIRED Like every real light meter, the LM-3000 requires a diffuser to measure accurately. A diffuser scatters incoming light evenly on the sensor and prevents hotspots. While it may sound complex, the solution is surprisingly easy. You have two options: 1) Easily build a diffuser yourself in less than a minute using standard printer paper. This is accurate enough for most use cases. 2) Get the dedicated Diffuser Accessory (free worldwide shipping) for best accuracy and convenience. More details on https://lightray.io/diffuser/ (!) Avoid apps that don’t require a diffuser! They are inaccurate because they ignore the basic physics of light measurement. TRY BEFORE YOU BUY The LM-3000 is free to download and comes with a free trial period. The trial period lasts for two non-consecutive days, giving you enough time to see if the app fits your needs. The status of your free trial will be shown as the "battery level" on the top right of the LM-3000's display and on the "Battery Status" screen. Once your light meter's "battery" is depleted, you may choose a Charging Option to keep using the app. You can pick what works best for you: → Single Charge — top-up for another 48 hours (perfect for occasional use), → Continuous Charging — a monthly subscription (great if you use it regularly), → Unlimited Battery — a one-time purchase for unlimited lifetime access LM-3000 is the result of over five years of dedicated research and development, ensuring you get a tool that is precise and reliable. Every in-app purchase supports future development and helps keep the app ad-free for everyone. As a member of 1% for the Planet, we donate at least one percent of all revenue to environmental non-profits — this is our way of giving back. ACCURACY Accuracy is not an afterthought — Apps developed by Lightray Innovation are developed according to the ISO/CIE 19476 standard. Thanks to RAW image processing and a default calibration per device model they’re able to match the performance of high quality traditional hardware light meters. To ensure quality we rigorously test our apps regularly on upcoming devices. DOWNLOAD FOR FREE. TRUSTED BY MILLIONS. LM-3000 is the go-to light meter for photographers, professionals, engineers, and lighting enthusiasts who rely on accurate measurements — not estimates or guesswork. Download for free today and experience the difference! See the app in action: https://youtu.be/EJW7NfE2qCk Terms and Conditions: https://lightray.io/lightmeter/terms/ Privacy Policy: https://lightray.io/lightmeter/privacy/

Ratings & Reviews

4.5

out of 5

2.4K Ratings

Well done
05/15/2023

Arizona_Lion
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
Well done
05/15/2023

Arizona_Lion

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 05/20/2023
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
This is a scam
04/16/2021

KJPA77
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
This is a scam
04/16/2021

KJPA77

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 04/16/2021
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
If you can read and aren’t lazy, you’ll love this app!!
04/12/2025

Uniquer_Nickname
Not having the budget for a pricey light meter I looked into potential apps and found this one. I read the developers description and the app manual and followed the directions and violà - it worked like a charm!!! It was SO EASY to try out the app prior to paying the very small, very reasonable one-time price!! As long as you aren’t an idiot who lacks self-awareness, and take the 1-2 minutes to read the description and instructions, then this is the app for you!!

Developer Response
Hi Uniquer_Nickname,Thank you so much for this feedback 🫶🙏 It's terrific to hear that you appreciate all the thoughts we have put into the app to make it as easy and understandable as possible 🤓 It's very nice of you that you took the time to write this review and share your experience with our community, thanks a million 💌🤗🌟All the best,Angela and the Lightray team
If you can read and aren’t lazy, you’ll love this app!!
04/12/2025

Uniquer_Nickname

Not having the budget for a pricey light meter I looked into potential apps and found this one. I read the developers description and the app manual and followed the directions and violà - it worked like a charm!!! It was SO EASY to try out the app prior to paying the very small, very reasonable one-time price!! As long as you aren’t an idiot who lacks self-awareness, and take the 1-2 minutes to read the description and instructions, then this is the app for you!!
Developer Response 04/14/2025
Hi Uniquer_Nickname,Thank you so much for this feedback 🫶🙏 It's terrific to hear that you appreciate all the thoughts we have put into the app to make it as easy and understandable as possible 🤓 It's very nice of you that you took the time to write this review and share your experience with our community, thanks a million 💌🤗🌟All the best,Angela and the Lightray team
Absolutely Amazing
06/03/2023

约礼
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!Update: 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
Absolutely Amazing
06/03/2023

约礼

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!Update: 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 06/23/2023
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

This update adds support for Japanese, expanding availability to more users. It also resolves an issue that caused the accessory crosshair placement to appear misaligned on the iPhone 12 mini.

Version 4.4.1

2d ago

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