Did you stop reading at post #11?
If you look at post #15 I did a step down test and got 1 minute and 10 seconds before it slowly started ramping down. My light was already a bit hot, though. Reviewers like Lock got about 3 minutes before a big ramp down. You should read his review. He’s got all kinds of charts and graphs and pretty pictures.
Also, ChibiM did a review here. He has some nice outdoor video.
My only video camera is my Note 4 phone and the video is always too dark. I’m new to doing reviews, this is my first, so I’m lucky to pack as much info as I can here. 