Cree T6 performance not outdoing my AA2 turbo mateys...?

Hi people of the light, I have a case of LED uncertainty for you if you wouldn't mind helping...


I have two lights:




Quark AA2 turbo - Cree XP-G R5 edition = rated at 206 lumens

UltraFire 501b 1 x 18650 - XM-L t6 = rated at 1000 lumens




Understandably the ultrafire is going to be over rated, and the quark may be slightly under rated.


But, the t6 ultrafire is no brighter than the quark r5.


Understandably the 18650 battery I bought was a cheap one, but it came in the post ready charged @ 3.9V. Is there a chance it drops a lot when the t6 draws power, do I need to measure it when in circuit. Or is my driver just poop?


The hot spot is slightly wider on the ultrafire, and so the throw is longer on the quark.


I'm not too fused, it was only a tenner, and the quark cost me 80quid a couple years ago. But I was expecting at least 600+lumens out of this ultrafire and it certainly didn't blow me away when I switched it on.


I take it you can't run two 18650's in series with an extender tube as it'l blow it? And running parallel surely lengthens battery life instead of increasing brightness?

As I say it's not much difference, I'd say the t6 looks slightly cooler in colour, maybe very 'slighty' brighter, but the throw is not as good as the quark.


anyone knowing the score on these could shed some, light on the matter *cough* would be very helpful


thanks

tom

Ultrafire may be slightly brighter, thing is - XM-L has very very floody beam which subjectively looks significantly less bright than it really is. Quark with Turbo head and XP-G has quite concentrated beam that appears brighter. I had really good XM-L module (about 3A to the emitter which is pretty close to 700 lumens out of the front) and I was dissappointed. Heavily driven XM-L can match XP-G in throw but in such small reflector - won't outthrow it. Brightness isn't everything.

Do a quick ceiling bouce comparison and report back. If the ultrafire is still not brighter then, you've got a bad driver or a bad battery. My XML lights are MUCH brighter than my xpgs. High lux (brighter hotspot) doesnt necessarily mean more flux (lumen) output. The XML die area is more than twice the size of the xpg die and has a corresponding lower surface brightness, thus it will have a lower throw.

Cheap batteries will definitely limit your output with that light.
Yes, the voltage will definitely drop a lot (how much will depend on the quality and characteristics of the battery), and is probably dropping low enough to drop below regulation.

yifu said:

Do a quick ceiling bouce comparison and report back. If the ultrafire is still not brighter then, you've got a bad driver or a bad battery. My XML lights are MUCH brighter than my xpgs. High lux (brighter hotspot) doesnt necessarily mean more flux (lumen) output. The XML die area is more than twice the size of the xpg die and has a corresponding lower surface brightness, thus it will have a lower throw.

Click to expand...

This.

To do the ceiling bounce test go into a dark room. Turn a light on and point it at the ceiling. Then look at something on the floor. Do not look at the ceiling. Repeat with your other light.

Because of the XML's wide diffuse hotspot it may look less bright when you look at the hotspot on the ceiling. But if you compare how well it's lighting up the floor it should be brighter than the XPG, proving that the total light output of the XML is higher.

The T6 XM-L is only about 600 real OTF lumens at 2.8A-3A in most every light

If your light is DD then you need a good AW or IMR to see those potential 600-700 lumens