Overall its great and surprisingly accurate
It is useful but not easy to use
Response from developer
You're right, I don't have a How-to for that. In a nutshell: measure one light; hit EXP LOCK, turn DIFFERENCE MEASUREMENT on, then tap the screen to lock the reading. While the lock is on, you'll see the difference between the locked reading and the current reading for both exposure and color. I hope to make some tutorial videos later this summer, but that'll depend on my work schedule, so I can't promise anything.
Handy to have..
Response from developer
Thanks for taking the time to post a positive review. I appreciate it!
A gimmick
After I purchased I finally read the fine print in the manual that says “tint correction values shown are appropriate for full spectrum sources with fluorescent LED’s and other “discontinuous spectrum sources” you typically need 1/2 to 2/3 of the tint correction shown.
Response from developer
Yes, a $25 app running on the $15 camera module built into a phone needs calibration for best results! For color, you can get a spot-on incandescent source (a light bulb) for about $2. For exposure, use any other light meter or camera that has an exposure readout. You can also calibrate by taking a reading, shooting a gray card using that reading, and measuring the resulting gray level in the image; if you're shooting film, a bracketing test can give you your needed correction in one go, even using a fully manual camera without its own exposure meter. As the instructions say, lux/fc won't change as you adjust compensation, but once you set calibration they *will* change. And no, they probably will not perfectly match your other meter, as Cine Meter II can only be adjusted to 1/10 stop accuracy, not to +/- 1 lux or fc (none of my four calibrated pro meters perfectly match each other in lux/fc mode either, even though they match to within 1/10 stop in aperture reading). Tint corrections are as accurate as with any other tristimulus meter (e.g. Sekonic C-500) but spiky spectra can fool all such devices. You need a spectrometer ($1200+) for more accurate readings; that's just the nature of the technology. See https://www.dvinfo.net/article/production/lighting/on-the-color-of-light-and-the-measurement-thereof.html for a discussion of the problem; see https://cinematography.net/LED-Camera/LED-Camera-Index.html for some real-world measurements.
