Photone - Grow Light Meter

Name: Photone - Grow Light Meter
Rating: 4.6 (4626 reviews)
Author: Lightray Innovation GmbH

Perfectly light your plants!

Free · In‑App Purchases

4.6K Ratings
Ages

4+
Years
Category

Utilities
Developer

Lightray Innovation GmbH
Language

EN
+ 7 More
Size

21.5
MB

Take the guesswork out of plant lighting with Photone, the most accurate plant light meter app. Measure PAR, PPFD, DLI, lux, foot-candles, and color temperature (kelvin) directly with your phone or tablet. To measure light with research-grade accuracy, Photone uses the most precise sensor in your device: the camera. Its unique measurement algorithm works directly with the RAW camera sensor data to capture true light intensity. This allows Photone to rival professional handheld PAR meters in accuracy and go even further by helping you interpret the numbers with in-app guides, tools, and additional features. MEASUREMENTS ⎷ Photosynthetically Active Radiation (PAR) as PPFD in µmol/m²/s ⎷ Daily Light Integral (DLI) in mol/m²/d ⎷ Illuminance in lux or foot-candles ⎷ Light color temperature in kelvin * ⎷ Extended PAR (ePAR) including far-red light (ePPFD, eDLI) * FEATURES ⎷ Industry-leading accuracy, comparable to professional PAR quantum sensors ⎷ Pre-calibrated for your specific device ⎷ No ads ⎷ In-app guides ⎷ Light source selection for every type of grow light (LED, HPS, CMH, etc.) * ⎷ Average and peak readings * ⎷ Plant light calculator ⎷ Hands-free “read aloud” function * ⎷ Special underwater measurement mode * ⎷ Custom calibration option to align readings to another meter ⎷ Premium support for advanced grow questions * * These features require an in-app purchase to fully unlock DIFFUSER REQUIRED Like every real light meter, Photone 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/. (!) Do not rely on apps that do not require a diffuser. They are inaccurate because they ignore the basic physics of light measurement. UPGRADE OPTIONS Photone is free to download and use with all basic features without any ads or hidden costs. To unleash its full potential, Photone offers two types of upgrades: → Lifetime unlocks — one-time purchase, always restorable via your Apple Account → Pro subscription — full access for as long as you subscribe, cancel anytime Photone took more than 5 years of R&D to develop. Upgrading not only unlocks powerful features, but also supports future development and keeps 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 — so every purchase helps both your plants and the planet. DOWNLOAD FOR FREE. TRUSTED BY MILLIONS. Optimized for plant growers and indoor gardeners – whether you're growing in a grow tent, greenhouse, hydroponics system, an aquarium, or are just looking for the best quantum meter app for your LED grow lights, Photone has got you covered. Terms and Conditions: https://growlightmeter.com/terms/ Privacy Policy: https://growlightmeter.com/privacy/

Ratings & Reviews

4.6

out of 5

4.6K Ratings

Useful and user friendly with a very involved attentive developer!
01/21/2020

vitvorg
Best app on the AppStore to estimate PPFD for growing plants. I’m a botanist, and so I know this app won’t replace a $400 par meter, but for quick estimations with your phone? This app is more than worth it. The hold feature is super useful. The background shows a grainy picture that gives you instant feedback that you are aiming your phone correctly, which is a unique feature that even the expensive PAR meters do not have. A suggestion to the developer for a future update would be for the background preview picture to freeze when the hold option is used. The hold option right now freezes the reading which is useful for measuring at actual leaf locations and orientations, but the background picture does not freeze with the reading. It would be amazing for the background image to freeze with the hold measurement, so when you pull your phone back you could see that you were aiming the phone correctly and you could see what you were aiming at when the hold measurement was taken.

Developer Response
Thank you very much for your kind and useful review! We will definitely consider the background image hold for a future release!
Useful and user friendly with a very involved attentive developer!
01/21/2020

vitvorg

Best app on the AppStore to estimate PPFD for growing plants. I’m a botanist, and so I know this app won’t replace a $400 par meter, but for quick estimations with your phone? This app is more than worth it. The hold feature is super useful. The background shows a grainy picture that gives you instant feedback that you are aiming your phone correctly, which is a unique feature that even the expensive PAR meters do not have. A suggestion to the developer for a future update would be for the background preview picture to freeze when the hold option is used. The hold option right now freezes the reading which is useful for measuring at actual leaf locations and orientations, but the background picture does not freeze with the reading. It would be amazing for the background image to freeze with the hold measurement, so when you pull your phone back you could see that you were aiming the phone correctly and you could see what you were aiming at when the hold measurement was taken.
Developer Response 01/21/2020
Thank you very much for your kind and useful review! We will definitely consider the background image hold for a future release!
I put my foot in my mouth.
07/26/2020

Funmcfunster
Originally, I had written a review stating how displeased I was for paying $5 for the Full-Spec LED addon. Then, I decided to see what others had said in their reviews of the app, and found an interesting bit of information that really helped me. I was getting inaccurate PPFD reading (300 directly next to a light source for plant cultivation), and was absolutely baffled by the number I got. However, I noticed multiple people, as well as the developer state that the use of a diffuser (like a tissue) is important in some instances. I just tried this and feel the PAR reading is incredibly more accurate than what I originally thought it to be. My apologies to the developer, and thank you to everyone for bringing useful information to the reviews. I would certainly now recommend this app knowing what I do.

Developer Response
Hi Funmcfunster,Thank you very much for your review! We greatly appreciate your insight and are happy that you get good use of our app! Best regards,Dominik
I put my foot in my mouth.
07/26/2020

Funmcfunster

Originally, I had written a review stating how displeased I was for paying $5 for the Full-Spec LED addon. Then, I decided to see what others had said in their reviews of the app, and found an interesting bit of information that really helped me. I was getting inaccurate PPFD reading (300 directly next to a light source for plant cultivation), and was absolutely baffled by the number I got. However, I noticed multiple people, as well as the developer state that the use of a diffuser (like a tissue) is important in some instances. I just tried this and feel the PAR reading is incredibly more accurate than what I originally thought it to be. My apologies to the developer, and thank you to everyone for bringing useful information to the reviews. I would certainly now recommend this app knowing what I do.
Developer Response 07/29/2020
Hi Funmcfunster,Thank you very much for your review! We greatly appreciate your insight and are happy that you get good use of our app! Best regards,Dominik
Kind of pointless
07/22/2023

Ndustrialhippie
This app caught my attention. I recently installed some grow lights and I simply want to know how far they should be from my plants. Was going to buy a light meter, but then this app says “free” on it. Thought I’d try it out. Well here’s the catch. It’s free to download, but you have to pay for anything actually useful. Theoretically, I’m fine with that. But you have to pay for each individual kind of light. You have to pay for information on what measurements mean. Really? What if, after spending all this money, you find the information is wrong? You can choose to unlock everything for a monthly fee or a onetime fee of $80. But here’s the thing…that same cost will buy a very decent light meter. You can buy a mediocre meter for less than half. And with this app, they insist you make a filter. And seriously, they INSIST. Like the alert will not go away even after you dismiss it, so the warning blocks measurements even after you have done a onetime payment to unlock something. Seriously? I’m just going to buy a light meter without all the hassle, thanks. Recommendation: Save your money and buy a meter instead.

Developer Response
Hi yungstud,Thanks for your detailed inputs 🙏You’re right, Photone is free to download and use. Additionally, there are various upgrades available. For many of our users, the app suffices without any upgrade purchases. If your use case requires an upgrade, you can first try the app, and see that it works and actually fits your needs without any cost. For example, to check how far your lights need to be from your plants you just need the right light source setting which is either free or $6. No matter if and which upgrade you choose, you will always spend way less cash than for a decent handheld PAR meter which comes in at around $600. Even better, Photone offers many more features like DLI, CCT, a plant lighting calculator, in-depth guides, and much more that you won’t get out of a simple handheld meter.As you’ve mentioned, a diffuser is required for accurate absolute measurements. Without it, you could only use the readings to compare them relatively. We’ve made this a bit “pushy” on purpose to prevent users from false measurements. If you're sure you'd want that, you could also disable the detection within the settings.I hope this clears things up a bit 🙂Best,Dominik and the Photone Team
Kind of pointless
07/22/2023

Ndustrialhippie

This app caught my attention. I recently installed some grow lights and I simply want to know how far they should be from my plants. Was going to buy a light meter, but then this app says “free” on it. Thought I’d try it out. Well here’s the catch. It’s free to download, but you have to pay for anything actually useful. Theoretically, I’m fine with that. But you have to pay for each individual kind of light. You have to pay for information on what measurements mean. Really? What if, after spending all this money, you find the information is wrong? You can choose to unlock everything for a monthly fee or a onetime fee of $80. But here’s the thing…that same cost will buy a very decent light meter. You can buy a mediocre meter for less than half. And with this app, they insist you make a filter. And seriously, they INSIST. Like the alert will not go away even after you dismiss it, so the warning blocks measurements even after you have done a onetime payment to unlock something. Seriously? I’m just going to buy a light meter without all the hassle, thanks. Recommendation: Save your money and buy a meter instead.
Developer Response 07/25/2023
Hi yungstud,Thanks for your detailed inputs 🙏You’re right, Photone is free to download and use. Additionally, there are various upgrades available. For many of our users, the app suffices without any upgrade purchases. If your use case requires an upgrade, you can first try the app, and see that it works and actually fits your needs without any cost. For example, to check how far your lights need to be from your plants you just need the right light source setting which is either free or $6. No matter if and which upgrade you choose, you will always spend way less cash than for a decent handheld PAR meter which comes in at around $600. Even better, Photone offers many more features like DLI, CCT, a plant lighting calculator, in-depth guides, and much more that you won’t get out of a simple handheld meter.As you’ve mentioned, a diffuser is required for accurate absolute measurements. Without it, you could only use the readings to compare them relatively. We’ve made this a bit “pushy” on purpose to prevent users from false measurements. If you're sure you'd want that, you could also disable the detection within the settings.I hope this clears things up a bit 🙂Best,Dominik and the Photone Team
Amazing app
07/25/2022

Blackout9642
Only reason I gave 4 stars is due to the fact that this is the only device I have used to measure light output of my full spectrum LED’s. So I’m not entirely sure how accurate its measurements are, or what the standard deviation of the measurements would be. One thing that could be added is a standardized diffuser that would be consistent, it worries me that if I don’t use the exact same thickness and type of paper every-time I may get inaccurate readings. However from the experience I have with the app it works amazingly and seems to give me relatively accurate readouts within a few 1000 Lux or a dozen or so par from what is advertised by the manufacturer of my current light and from what I’ve seen online people using high end spectrometers and other devices get similar data readouts… if your new to growing or just want a general idea… this app is the way to go 1,000%. Will not let you down just take your readings with a grain of salt.

Developer Response
Hi Blackout9642,Thank you for your detailed review and your input! Happy to hear that our app is helpful to you. The deviation between devices is low as we've tested ALL supported iOS devices in our light lab and created specific factory calibrations for them. So as long as you're using the same diffuser, the absolute measurement is comparable between devices. What is introducing a bit of variation (~6% standard deviation in our tests) is the paper diffuser itself due to placement and paper structure. Your input on this is very valuable. You can also reach out to our support if anything else / related comes up.An update would be greatly appreciated when you've had the chance to test multiple devices :) Best regards,Dominik and the Photone Team
Amazing app
07/25/2022

Blackout9642

Only reason I gave 4 stars is due to the fact that this is the only device I have used to measure light output of my full spectrum LED’s. So I’m not entirely sure how accurate its measurements are, or what the standard deviation of the measurements would be. One thing that could be added is a standardized diffuser that would be consistent, it worries me that if I don’t use the exact same thickness and type of paper every-time I may get inaccurate readings. However from the experience I have with the app it works amazingly and seems to give me relatively accurate readouts within a few 1000 Lux or a dozen or so par from what is advertised by the manufacturer of my current light and from what I’ve seen online people using high end spectrometers and other devices get similar data readouts… if your new to growing or just want a general idea… this app is the way to go 1,000%. Will not let you down just take your readings with a grain of salt.
Developer Response 08/06/2022
Hi Blackout9642,Thank you for your detailed review and your input! Happy to hear that our app is helpful to you. The deviation between devices is low as we've tested ALL supported iOS devices in our light lab and created specific factory calibrations for them. So as long as you're using the same diffuser, the absolute measurement is comparable between devices. What is introducing a bit of variation (~6% standard deviation in our tests) is the paper diffuser itself due to placement and paper structure. Your input on this is very valuable. You can also reach out to our support if anything else / related comes up.An update would be greatly appreciated when you've had the chance to test multiple devices :) Best regards,Dominik and the Photone Team

This update fixes a rare bug leading to a crash when starting the app.

Version 4.1.2

Nov 11

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