Does the U2 still have the "donut hole" problem?

I've read in the past here that the U2 has flawed beam - a donut hole in the middle of the beam. Is that still the case? I've been thinking about getting one the next time they come up for sale in the For Sale forum here at CPF. Has Surefire even acknowledged the problem?

I just sent my U2 back to Surefire for correction of a pretty noticeable donut hole. I purchased this light in January so unless I got a light that had sat on the shelf for awhile, it would appear that Surefire has not worked out this problem completely.

The people in the customer service department did not blink before issuing an RMA number for me to use to return the light when I informed them that the reason that I was sending it back was for correction of a dark spot in the middle of the beam. I am hoping that when I get it back, it will have a "flawless beam".

I love this light and almost did not want to send it back as I knew that I would be without it for a couple of weeks.

I have looked at the beam from an L7, and it did not have the same donut hole problem so I am hopeful that Surefire can resolve the matter.

-Goatee

Interesting. I was thinking about the L2 instead, but it doesn't have as tight of a beam as the U2. I like tight beams, not floodies....

Basically any Luxeon V light might have a donut hole in the beam. It's not something specific to Surefire, and certainly not the U2 specifically. The problem is that Luxeon V LEDs are really four diodes placed closely together, but they're not always quite close enough and as a result you can get a dark spot in the middle.

Just as with tint, donut holes fall under the "Luxeon lottery". Whenever you buy a Luxeon, you'll probably get a good tint, but there's a distinct possibility you'll get a bad tint. Whenever you buy a Luxeon V (like the U2), you probably won't get a bad donut hole, but there's a distinct possibility that you will. It makes not difference what model Surefire you get, all U2s are different and all L2s are different. There's nothing Surefire can do to fix the donut hole problem, or tint problems, except maybe start rejecting some of the worse LEDs that they are currently putting in their lights, but I doubt they would do this as it would cut into profits. You just have to hope you don't get a donut hole and/or and terrible tint when you buy Luxeon V lights.

Personally, I don't think it's a good reason not to buy Luxeon lights, but some people are really bothered by "off" tints or donut holes.

I don't consider it a "problem". At most ranges, the donut holes are unnoticable. For practical use, its unnoticable at all ranges my opinion says. Only at certain ranges on a white wall can I notice that donut holes, and even then its minor.

Perhaps I've been lucky though.

Yeah, I thought it would matter to me too since they make a big deal about it here. Now that I've owned and used one for a while I couldn't care less. Great light with some serious flexibility. I think it's the best SF light. Don't worry about the donut hole. The tint of the beam is of way more importance to me.

I have 2 U2's, and have not noticed any "donut hole pattern" in the beam of either of them, nor on my best friend's U2.

Hmm, I do notice one if I put the light like, 1" from the wall! Other than that, just a nice even beam.

my u2 doesnt have the donut hole and it has a very bright slightly greenish/blue tint

KDOG3 said:

Interesting. I was thinking about the L2 instead, but it doesn't have as tight of a beam as the U2. I like tight beams, not floodies....

Click to expand...

Ummm, you do know that the U2 is a flooder as well right?

https://www.candlepowerforums.com/threads/104699

I would not consider mine a flooder. Mine has a very tight hot spot with a dim side spill. Must be a freak! Absolutely no donut hole, not even close up. Way cool light and my EDC.

the new reflector is supposed to deal with this issue (which is a property of LuxV emitters, not the U2) - you could still be getting older stock, though.

CBXER55, That's interesting because I've handled 3 U2's now and they were all on the flood side of things (note, the following is just for how much of the beam is used for a purpose, this has nothing to do with the overall power)

In my experience...

ALL FLOOD
-River Rock Lantern
-Inova X5 (wide flood)
-Surefire L2 (Nearly all flood)
-Surefire U2 (biased towards flood)
-Streamlight SL-20
BALANCE---Surefire 6P (P61 bulb)
-HDS EDC 60 Basic (biased towards throw)
-Gerber LX 3.0 (strong throw with medium sidespill)
-Night Ops Gladius (strong bias towards throw)
-Inova T4 (pretty tight throw)
-Striker VG (almost totally throw)
-River Rock 2xC or 2xAA (only throw, no sidespill)
ALL THROW