Tom_E
(Tom E)
124
It's true having 4 cells vs. 3 is an advantage for the Q8 Pro and should result in higher output with all other things the same, but the 15000 lumens rating is not so out of the question. I did several measurements on mine and the best #'s I got on fully charged VTC5D's were:
- 16422 at start, 13600 at 30 secs (my calibration based on high end manufacturer ratings)
or
- 14635 at start, 12120 at 30 secs (mauuka calibrated)
The VTC5D and Samsung 25S are the best performing 18650 cells available, at least with capacity from 2500 mAh and above.
So I'll give them credit for being in the ballpark for the HK04, but yes, slightly over rated.
I don't have a Q8 Pro to test and compare with, but I can tell you the HK04 has some advantages in that they are using quality springs, better than the Q8's (if the Q8 Pro is the same as standard Q8's), and the driver is more advanced with dual FET's that in theory should help for the 4 high powered LED's:

It's all a matter of the tradeoff's of a more compact (thinner) design vs. 1 more cell.
The 1400 lux vs. 1100 lux may depend on the cells -- d_t_a did not mention exactly what cells were used. Still, I'm a little surprised the difference is that large, if what is being measured is a true reflection of lumens.