Ya, it’s tricky and many considerations have to be included.
I once thought about darkening certain side walls to reduce wall reflection, but i didn’t do it because it’s still unscientific home project, and that’s just one of many factors. Also my wife would kill me.
I do ceilling bounce every night now, but for lighting purpose only :sunglasses: 
When you lift the light closer to the ceiling it changes the readings because the distance is shortened and you won’t get a fair comparison. I tried that before but decided that was a flawed method.
I also do ceiling bounce every night too for room lighting ever since I got those nice 90CRI lights. The light quality is better than my ceiling fixtures. Nice to know someone else does that too
Just done a 10 minute turbo runtime test with no fan and the result was quite different!
Turbo was 10 secs shorter, It couldn’t sustain any significant brightness level, dropped to around 6,000 lumens, couldn’t hold turbo at all at the 9 minute mark when reapplied, and the handle and head got 6c and 9c hotter.
The Fandle works.
I do ceiling bounce because 60,000 lumen calibrating spheres are worth more than Hanko’s Aston Martin.
my flooders are returning 61k-68k, basically I’m thinking its a 64k light. You’re never gonna get a like for like beam so averages are needed for ceiling bounce.
It could be more than 64k as it really does put a lot of light into the spill. Light the lux meter struggles to account for.
It’s an amazing light.
My x70 fits fine in my lumen tube and only reads 45k. Flashaholics; you even admitted that lumens from ceiling bouce are unreliable. I am telling you that in a controlled environment this light is hitting only 45k lumens. Let’s wait for others numbers
As I’ve red, a goniophotometer is more appropriate for measuring light fixtures and an integrating sphere for light sources (single LEDs). Anyway, the price for a goniophotometer is anywhere from 3000$ to 50000$. So… maybe if I write a nice letter to Santa? 
my "ceiling bounce"
Lumen testing acebeam x70
Are you sure your X70 is NOT in ECO Mode?
Besides fitting, lux meter has ranges. It could be lux meter range hitting saturation or almost overload at high range. Also ranges are not flat, so a setup will be only fine from certain low lumens until certain maximum lumens measurement, i mean there’s usable dynamic range for a setup.
Positive
I just watched your video, i think X70 is not sitting as close inside the tube like other lights. Can you repeat the 5000 and 9000 lumens test with x10 too?
Sure let me top off the batteries.
You want a new multiplier too? Batterys are charging right now.
Would you like to me change any other variables?
May be repeat the test with settings below:
x10 on meter
Lift the 3 smaller lights to same height that X70 sits on
I will do that right now. I’ll post up another video momentarily.
Thanks for the efforts.
Maybe you can also check lux reading consistency for x1 and x10 using 1000lumens and 9000lumens.
Very very interesting
The solution to find out the truth about the lumen output would be to use the services of a photometry lab with professional, certified optics equipment. Some one did this a while ago in Germany. I could find this: http://taschenlampen-tests.de/?p=11717. I have no idea how expensive such a service would be. I am trying to find such a laboratory but in Romania there aren’t many.
Test 2
