As an alternative for a light meter, I realized that most smartphones had built-in light meters so that it can automatically control its screen brightness depending on the environment.
I’ve tested a couple lux meter apps, and the best one I found for Android was called Physics Toolbox Light Sensor by Vieyra Software. It graphically plots the light intensity using the sensor in front of the phone.
Screenshots:
I’m using a Nexus 4, and it can measure 0-10K lux in 1 lux resolution.
Most of my lights saturate my sensor at 1m, so I need to back out, and recalculate it. (Candella = Lux x Distance Squared)
For iOS users… I couldn’t find an app that would graph the lux values.
I see graphing as an important feature because if you tailstand your light, you can measure the drop in output as the LED heats up and become less efficient.
Hope you found this post helpful and it would be great if you could share other apps as well.
Cheers!
Edit: I must admit that the app is slightly buggy, as I couldn’t control the graph’s x-axis, the time. It would scroll through as it recorded the lux measurements, but I couldn’t find a way to scroll back.
I had started a thread on this a while ago, but didn't get no interest really. So far all the phones I tried had horrible accuracy, with huge jumps in readings... May have to try my new phone now.
Sorry about that Pulsar, I did search through BLF about the same concept but the only page I found was two years old and it wasn’t made by you.
My Nexus 4 (Slewflash’s as well) seem to be reading pretty accurately, but it does get saturated too quickly than I would like. Which phone are you using?
Cool. I just got an S4 and it works much better than the s2. Androsensor works and you can record the graph it spits out to a csv file but none of my android apps will read it. the temp, humidity and atmospheric pressure readings are what I originally downloaded it for.
Thanks for the great idea. Never thought of this before.
I have a iphone 4 and just tried out one free ap called luxmeter. Seems like it is working fine. The max lux I can get on it is more than 30k with my nichia 219 at 1.75A.
i have tried it with the samsung sidekick 4g, htc inspire 4g, i think my tmobile g1... and i think another one i cant remember... i will try my new htc one x. im not sure if the iphone has this capability, if it does i will try my fiances 4s
if i remember correctly, all the ones i tried got saturated very quick, and jumped up in readings by something like 500 or 5000
its no big deal, the thread i made had basically no data in it. if this one grows and gets lots of data all the beter
Nice, good to know that the iPhone 4 has a max reading of 30K lux, thanks for sharing.
Yup, it would be great to have a list of phones that worked well as a lux meter.
I was even thinking of using an ND filter to increase the maximum readings… but a quick search showed me that they’re more expensive than a regular light meter! :~
I just tried it on my LG Optimus LTE (Nitro HD) and it has a range up to 10k lux. Not overly accurate though compared to a real lux meter.
More fun was the accelerometer app. Not that I need any more reasons to toss my phone around
Just downloaded about six of these apps and will run a few tests to see which is the most accurate for my phone (Samsung Galaxy Nexus) and report back. I don’t think my phone has that great of a light sensor on it though but it could be a great way to at least compare some of my lights. We’ll see….
However, I think that it’s more about the features instead of the accuracy, because I believe that raw data that the light sensor spits out will be the same. I think it’s important how the app handles the data, and graphs it well so that us flashaholics can easily interpret it.
It also has a multiplier adjustment so if you know the true lux of your light you can adjust your app to reflect true lux. This test was done with a Convoy C8 T6 @2.8A. Didnt dare try my Sky Ray M4 since it maxed out on the Convoy
