3.8
out of 5
120 Ratings
Light Meter - lux and foot candle measurement tool
Ratings & Reviews
I purchased this app to compare illumination levels in my home. Since I wanted to compare lighting levels in different areas rather than know the specific lux/foot candle illumination values I can't attest to it's accuracy. While the app is simple to use I will note that on an IPad 3 (IOS 9) using the back camera resulted in readings approximately 3 times higher than those registered using the front facing camera. Given the larger lens opening I can understand why but which value is correct? Also, the app got set to "outdoor" at one point and the only way I could get back to the "indoor" setting was to delete it and reinstall. It would be helpful to have a better way to clear values once a reading has been taken as the current method doesn't seem to work all that well.
Do not expect customer service to ever answer any questions or emails.Light levels are absolute levels of brightness. Therefore, it's very odd that there is an indoor/outdoor button to set. The two settings get very different readings. Why? It should not matter whether the reading is indoors or outdoors. The number is simply a function of how bright it is.Other apps on the App Store will also tell you what the color temperature of the light is. That can be very useful in knowing whether it's bluish or yellow-ish. This app does not give you that.
Developer ResponseHi,thank you for using Light Meter and sorry for inconvenience. The app is using Neural Networks to measure light levels. Since we don't have access to the light sensor directly we have to approximate measurements from camera readings. And you're right i'm using brightness level to measure but not only. Exposure time. F-number and other readings. While calibrating i noticed that my neural network shows better results if I split measurement modes into indoor/outdoor. It helped me to improve precision. At the moment sum squared error is about 9% on 5000+ calibration samples. I bet it's the best result on App Store. And thank you for a nice idea. I'll add color temperature measurement mode with upcoming update.
My I phone has a front and back side camera. I have a screen protector on the face that affects the readings. I make sure I use the back side camera for most accurate results with this app. Can’t speak to accuracy compared to a standard. This app works great for my needs.
I am extremely pleased with this application. This is a app you really need to measure light intensity. Interface and design are so simple, makes this app easy to use, with features as realtime measurements, Indoor and outdoor modes. This is great application. It works very well, I will share with friends use.
I spent over 60 years in electro optical engineering, and this is by far the best two dollars I ever spent. I agree the color temperature would be a big plus, and to be able to see the image would be very helpful to get things pointed the right way.
Disregard any negative comments! From an app developer standpoint I appreciate the effort put into this app. For reading light values from a camera, this is very accurate. Buying this app you have to know that it's coming from an iPhone, not a comercial light meter! Great job!