Here is one inexpensive meter to stay away from http://www.cem-meter.com.cn/DT-1301.htm, it reads way low. Its all over eBay by various dealers and rebranded under differant names and model numbers. Its a CEM DT-1301. My first Tiablo A9 logged in at just under 15k lux, I thought it was the light. My second A9 was about the same, close to 15k . Most others here were getting close to 20k with the A9. I also looked up tests on other lights I have, my readings were always far under what everyone else was getting.