Welcome to BLF jstay!
Is it a bubble as you say, or a black spot (as it looks like in the picture)? Perhaps you can take a picture with the light off?
If it is a clear bubble on the led dome it does not absorb light and warm up, so it does not have to affect the lifetime of the led. But you never know. Bubbles on the led dome are sometimes caused by a hot solder iron slightly touching it.
Hi djozz,
thanks for your quick response. Yeah, I am quite concerned about this so I created a blf account to ask more about it. 
It seems to be a bubble rather than a black spot. With the light off, it (the bubble) cannot be seen with the naked eye. On camera I am quite certain it is not possible as well.
when the light gets brighter as it is ramped up, the bubble cannot be seen as well as the light blinds it out. So, the bubble can only be seen in moon mode.
How serious is this issue, should I contact banggood? Or is this a non-issue which does not affect lifespan and performance?
thank you
This sounds like a completely new issue that nobody has ever heard of before. One would assume that Cree would have noticed that before selling the led.
What can you do though? I doubt banggood would allow you to return it because of that. Maybe you can use turbo quite a bit and see if the LED burns up or not. If it burns up within the warranty period then you could have it replaced. If it survives, then it likely won’t cause any problems later on.
I’m afraid that for the seller it is a non-issue until the led blows up, there is no way you can convince them that that tiny black spot is the start of a dying led. The best you can do I think, is do a test run on highest settting, when the light steps down after three minutes, ramp up to highest again and let the light get as hot as you can still touch it. If the led blows you have a case for Banggood, if it doesn’t you will have to live with a bubble in your led and some uncertainty.
Alright thanks JasonWW and djozz. How long /how many cycles should I let it run on turbo?
okay thanks ThrowMeInToDarkness. Yeah you happened to answer my question just as I was typing it!
Your bubble might also be just a tiny drop of flux which could easily be removed with Isopropylalcohol instead of completely destroying the LED.
@ Flashy Mike Yes that might be the case as well (hopefully) thanks for the idea.
Will dipping a cotton bud (also known as q-tip, ear cleaner etc) in 99% ipa and then lightly wiping the led dome do the trick without damaging?
sounds good, you will not destroy anything like that. Make sure that no cotton fibers are left behind on the dome, that can burn again by the heat of the very dense radiation.
Okay , will try that. Thanks for the idea
Probably yes, but don’t touch the front of the reflector. I strongly suggest to remove the reflector before cleaning.
Q-Tip is perfect.
ok thank you for the response.
to remove the reflector for blf q8, I just need to unscrew the top portion (silver aluminum ring, o ring , glass) and the reflector can be pulled upwards directly?
or do I need to unscrew the bottom including the driver circuits etc. ?
I’m afraid that you need to go all the way. Everything comes apart fine but this is it:
First unscrew the silver SS ring and remove the glass and large o-ring. Turn the head around.
Unscrew the driver and tilt it until you can get past it with a screwdriver. Inside the driver cavity first unscrew the big central screw then the two small screws. Then the reflector should fall down. Clean the led and reverse for assembly, take care to seat the reflector precisely on the the plastic centering rings around the led before tightening the screws in the driver cavity.
I so love this site.
Always a guru a click away. 
yeah I feel the same here. even though I’m a new member people help me voluntarily with nothing to gain. and it’s especially helpful for a newbie like me who’s worried things go wrong when yall guide me. Thank you.
update: I’ve contacted banggood about it, but they have not responded. most likely it’s a non issue, since I cycled it thrice and nothing has changed. but I’m using protected cells as the new unprotected haven’t arrived.
I’ve also bought another q8 as a spare, as I felt it’s a really good light even with this “defect”, and also since the banggood coupon code might expire soon. Hope that one is ok!
What banggood coupon do you have? I was looking for some type of coupon earlier.
Im using a code from https://m4dm4x.com/blf-q8-arrived/ which gives me about 45% off.
*edited to remove code and include website
I don’t think you are supposed to post that code openly. You need to go to M4D M4X’s website to get the code, and for him to get his commission. (I think)
Post 17,000!
(at the moment)