After TA confirmed my readings seem right in a pm I can confirm the brighter the light you use on the TA calibrating tube the more the reading will be off, a 1000 lumen light will read around 800 lumens and a 100000 light will read around 50000 lumens the the thing is utter garbage people. £132 down the drain…
Have you tested it with using a neutral density or other dimming filter in front of the meter. If the difference (lux ratio) between a low and high output light is different with the filter, the meter isn’t linear in the high end.
Can you please post some examples? All of the examples you have posted so far are very reasonable. Maybe not what you want to see but very reasonable to real world ANSI lumens.
Do tell, where are you getting a 100k lumen light? I would love to see that!
Also you posted above that a 1000 lumen rated light (PT16) read 950 lumens, why are you now saying it reads 800?
At a glace I do not have hardly any of those lights but the numbers all look VERY reasonable.
I do have a Q8 and I also get around 4600-4800 lumens with it depending on the batteries used.
Hopefully some other people with the sphere have some other lights to compare and we can find out if it is off or not.
The only reading that stands out as being abnormal is the X45, does seem odd for it to be reading that low when rated at 16k. Were the cells fully charged?
I don’t see the difference getting bigger on higher output lights compared to my readings.
Your X80 and S2R are both about 25% lower than mine.
And there can be as much as 20% difference between the same model of flashlights. And probably even more on the higher output ones where every little bit including the batteries matter.
Interesting, how stable are the readings from these lights in the lower modes?
KG, I assume that the batteries are fresh off the charger when you took these readings? If not can you take some more readings with freshly charged cells to confirm that is not the problem.
Also some readings with the lights in the low modes would be a good test for linearity.
Like maukka said the light absorption should be linear (and is in my own testing).
It would also make no sense for it to read the Q8 spot on and be way off for a light only slightly brighter. A few percent maybe but not a massive change. Something else must be going on.
The biggest problem I see so far is comparing the numbers to the factory ratings. See the Haikelite story above, they had the light tested much lower then the official ratings. Official ratings now days mean almost nothing.
Are all of the cells in the lights 100% freshly charged. High powered lights are very sensitive to changes in battery voltage and low cells can easily cause low readings. Also you are using high drain, unportected cells in them correct? Like 30Q or VTC6?
On most iffy diy systems the X45 and X80 come in way too low due to the sheer flood, I had to get around it with my system by moving the X45/80 forwards to impact as a thrower. The TA system is like a Zoomie flashlight that looses lumens as you zoom to a tighter beam as most of the light is absorbed in the flashlight’s walls. My Emisar D4 XP-L HI reads higher in the TA system than my Emisar D4 XP-L HI with diffused optics.
The Q8 is throwier than the similar rated D4 XP-L so records 1300 lumens more than an expected 500 lumens difference and circa 2000 more than the diffused D4 XP-L!!!
For the record, if there is indeed proven to be an issue with your sphere, I will make it right.
That said the numbers seem to be very reasonable so I want to wait for some other peopel to see this and hopfully be able to get some comparison numbers.
For this to happen the cells and charge status of them need to be known.
Can you please list what cells you are using and if they are freshly charged?
I’ve done the tests textbook like you wished, they get similar readings to ceiling bounce tests. In which the high lumen lights don’t seem to get as close to manufacturers claims, especially floody lights. They do if I lift the light towards the ceiling to match the hotspot of the light I’m getting a figure from. I.e. The DT70 gets 13000 and the X45 gets 11000 by lifting the light to match the spill area I got it to the widely accepted 14500 region.
All I can think is the more light you feed the TA tube the more light it retains, especially with all the diffusers, bounce back, twists and diffuser material, obviously the tube will favour certain beams and lumen ranges.
Though you doubt it it could be my meter playing up though, not being efficient??
On that X45, turbo is rated at 9,000 lm and turbo max is 16,500 lm.
Are you reading 8,000 lm on turbo max?
8000 lm seems like it might be on the first turbo setting.
If your reading 8000 lm on turbo max, what does it read on the other turbo setting, 4000 lm?
I would expect Acebeam to be a bit closer to spec than most other brands.
Also, as just a general thought, batteries with high internal resistance (like protected cells) or cells like Panny B that can’t do high loads can definitely prevent a light from doing it’s best output.
Like if you had 4 Panasonic NCR18650B 3400mah in your X45 then it would probably not be able to go into the turbo Max mode. Just as an example.