LightSpectrum Pro

I’m really impressed with what this app can do for its price and the fact that it runs in a iPhone. UI is a bit janky (iPhone 14 pro), but regardless this app blows anything else out of the water. Refraction box feature is really great and much more convenient then other diy solutions. It would be really nice if refraction box could be used for taking more measurements.

I have some LEDs where I know the wavelengths, and under some combination lighting conditions the app is super inaccurate—but under lots of conditions (including combination ones) it’s very accurate. Useful tool, overall. I wish they would fix the inaccuracies but I’m still glad I have this app; there’s no other app that has a full spectrogram right now.

This app needs to have crosshairs or circle at a point on the screen, to only take measurements. General averages of the picture isn’t a great feature. Spot metering will make this app awesome!

This inexpensive app does a great job on my iPhone of measuring light color temperature which is exactly what I wanted!

I used to use a $2,000 light meter to measure color temperature when I worked in the film industry. This meter costs only a few bucks and is almost as good. The app description says it’s within 8% of the actual color temperature, which in most circumstances is sufficient. I tested the app in a variety of environments; I.e. outdoor sunny, outdoor cloudy, interior lights, balanced to daylight, cool white, etc. and it worked great. If you’re doing scientific measurements it might not be what you need but for film and video it’s pretty great.

I have a flashlight collection with emitters that are color temp calibrated to temperatures such as 2000K, 2700K, 3500K, 4000K, 4500K, 5000K, 5400K, 6000K (and more!). I found that this app got CCT correct within 100-200K when used properly. I took a white sheet of paper, shined the light on the paper, then read the paper’s reflection. Aiming the app at the flashlight directly gave skewed results by 1000-2000K upwards. It’s so accurate that I had a light I had mislabeled as 6000K, and it kept coming up as 4950K. I checked the LED bin (XP-L HI V3 3A) and it was actually 5000K! So the 4950K was dead accurate. I did notice that as you move away from the 4000-6000K range, the ratings are less accurate. For example, my 2700K lights red as almost 3000K, and 2000K lights read as 2700K. My 660nm pure red lamp reads as 2400K. So keep that in mind. But this is a great value for $2!

I was overcharged the amount of $18.38 when I purchased this app. I need a refund and you need to fix this issue.

Some old-fashioned people think that a quality program should have no misspellings. So think about ‘cancel’ and ‘wavelength’, please. Aren’t you embarrassed by these errors?

App does not measure spectrum. iPhone does not have spectral sensor. I compared this apps readings to Sekonic C7000 spectrometer and a Photo Research PR670 ($20,000 instrument). This app’s readings are completely wrong.

First, the fact that it does what normally takes thousands of dollars in tools is fantastic. No, it's probably not nearly as accurate as pro devices to do this work and having said that, since I don't have access to pro-grade tools I cannot say how the accuracy of this compares. But now I have a way to quantify the various values of light sources, and most helpfully, I can compare them objectively. This is certainly an app that every art, theatre lighting and photography student should own. Such a good learning tool to see how light sources and color interact. For homeowners this tool helps sort through the spec's of the multitude of light bulbs at the big box stores. I'm using this on an iPhone 6s with no problems. My only complaints: -The interface can get cluttered. Using it in landscape mode helps that quite a bit. In portrait mode, at least on my little phone, things get piled on each other. Wish it would run on my older iPad! -The helpful explanatory tips are good, but I wish I could figure out how to shut them off. -I wish I could take screen shots in landscape view. Wish: -Now if it had a way to measure flicker of bulbs! Don't care, make it a separate app or make it a purchasable upgrade for this one. I'd buy it!