I’ve estimated my factor by measuring a handful of standard ‘name brand’ lights. Its basically all the ‘Stock’ lights in the list above & 1 or 2 additional ones thats not listed…
I don’t have the C8 mentioned above anymore, so cannot measure the tail amps. I’ve measured another C8 XP-L Hi V3 2B now and got 1625 lumens with turn-on and 1555 at 30s. Tail amps were measured at 5.0 amps after 30s with my fluke 374 clamp meter.
I don’t know about official tests here on the XP-L Hi V3, but Djozz did some testing on the XP-L Hi U5 - around 1600 lumens. According to he’s test, I believe my figures above might be in line. I’m definitely not saying Djozz’s figures are 100% accurate, this is the only figures I can bench against here.
But, I still have a good feeling about my figures measured above, and my current sphere multiplier. I believe its accurate to around 10% up or down. I can live with that.
You’ll see that some of my stock light measurements are below the advertised lumens, e.g. Maxtoch 2X. Its rated at 1300 lumens, I measured 1215. Same with the Thrunite T10. Its rated at 169 lumens, I measured 147. So, I did not just pick the highest multiplier possible, I did try to find a happy medium between my stock light measurements.
I should probably sign up for the light currently travelling the world to get our spheres in comparable state :).