New SF L4 dark spot in center beam

I recently purchased a second SF L4 from Surefire so I could covert my old L4 into a smaller E1E body with R123 li-ion and SF Z57 clicky switch (this TW4 setup almost as bright as L4-sweet!) Anyway I noticed a dark spot / donut hole in the central beam of my newly arrived SF L4 from about 5 to 12 feet away. Since SF has always stated perfect beam no dark spots, I returned it for another one. From Surefire Website: Why Buy SF? …"they produce optimal beams — brilliant light with no rings, hot spots, or shadows. They produce optimal beams — no dark holes, rings, hot spots, or shadows. When you own a SureFire flashlight, you own the best".

Customer service told me the shipping dept cannot open and check it for dark spots. So I returned the first one and got another one, same problem just not quite as bad but still very noticeable dark spot / donut hole.

I have been a loyal and extremely satisfied customer of SF torches for years, even got to meet Paul Kim (PK) Chief engineer @SF at a previous Shot show in Orlando, so I am really frustrated at this point since I can no longer boast of its perfect beam (L4) to others. My SF M6 and other torches don't have this problem.

I can't count how many SF lights I have convinced others to purchase because of my excitement and endorsements about the highest quality of their lights. Have any of you guys had this dark central spot problem? Maybe not everyone is a purist with high expectations that I have become accustom to from SF. Not trying to be a pain, just want the great torch I have come to expect.

On the positive side, both new L4 beams were whiter in tint and brighter than my older L4 beam. But no dark spot in my older L4 just perfect beam. New KL4 head serial numbers: A23151 and now received A22875. My old KL4 head #A06716. Any ideas on how to get an L4 without dark spots in center beam? Should I keep sending them back until I hit the perfect beam lotto luck of the draw? I paid top dollar directly from Surefire thinking I wouldn't have an issue like this. If this doesn't get resolved with SF, perhaps I could go to Bass Pro Shop locally and personally check the SF L4 beam prior to buying it. Any suggestions?

Someone here said that the donut may be caused by the LED itself and not the reflector. I recently got to swap out the Lux Vs of two KL4s. Both of them had donuts, but when i swapped out the LEDs, the donuts disappeared on both units. My personal suggestion? Get a latest generation KL1, swap out the optic with a McR20 reflector, change out the convex lens with a UCL lens and you're golden. You can even have the option of swapping out the LED for a premium U-binned Lux III.

Sorry to hear about your Cheerio. Have an L4 and it has a perfect beam. It took 3 of them to get it. returned 2 and the third one was the good one. I quit buying from surefire for the tint and cheerio effect of their l.e.d lights.

My L4 is new and has same beam pattern, I think it's normal, FR also described this in the L4 review, in practical use this really isn't noticeable for me. I also glad to hear that the new L4 is brighter than older one.

My L4 was fine however I have had three U2s and all have had a nasty donut.:thumbsdow My HDS has a perfect beam and in my opinion superior to Surefire.

I have a L4 with a perfect beam and with the Gizmo two way switch it is a awesome light especially with the 17670.

the next time you see paul kim, smack his face with the l4 and tell him you want a replacement from HIM.

disclaimer: him hammering your head with the 10watt LED prototype and then flashing the light at you is none of my business.

Donut hole is the sign of a perfectly focused reflector

GarageBoy said:

Donut hole is the sign of a perfectly focused reflector

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Huh?

There LuxV is a 4-die emitter with a center that does not emit light, so the ideal image of a luxV should have a center that is dimmer than the outer parts of the hot spot, the SF's aggressive oragne peel sometimes takes care of that but not always.

THe price you pay putting 4 1-w dies in a small area...

Sounds quite true. I have 3 SF lights using Lux V and only one of them has a barely noticeable donut hole. Any truth in the idea that if a Lux V were focused for throw, there would be a donut hole?

grnamin: The LED may be causing the donut hole dark spot I agree. But we shouldn't have to be the SF quality control by replacing LEDs, reflectors, lenses or whatever. But I appreciate your great suggestion and may do this mod if not remedied by SF.

skalomax: I may send this second SF L4 back to obtain a 3rd one which may be the charm as it took 3 trys for you.

Chao: I respectivefully disagree that the SF L4 donut hole dark spot is "normal". It may be that a batch of LEDs were not up to par and accepted for use by SF L4s when they shouldn't have been. Perhaps they felt many consumers either don't notice it or don't care so why keep the perfect beam they have earned a reputation for. I care. I buy SF torches because they aren't "average" but exceptional. If more compromise slowly slips into their products, they will lose the cutting edge they have worked so hard to obtain. To stay on top, SF will have to keep its customer base WOWED, impressed and excited about their products.

seaward: Was disappointed to hear the SF U2 has a donut hole also. I had been considering this adjustable beam intensity LED torch. For SF's top of the line LED, it should have a flawless beam. I also met Henry @ the Orlando Shot show few years ago. (who owns HDS Systems) He is meticulous in details and quality and a really nice guy too.

lrp: I may mod a two way switch for my TW4(KL4 head, E1E body,clicky switch). It's my EDC torch.

chesterqw: PK is busy working on designs for the new SF torches I'm sure and this a customer relations / SF quality reputation issue.

270winchester: The Lux V emitter may have a center spot that is dimmer but it should not be dark in my opinion. The overall beam should be fairly consistent as my older SF L4 beam demonstrates. Perhaps to obtain the increased output in brightness using these new emitters, the central beam had to be compromised in production. Steal from Peter to pay Paul. SF does not produce the LED emitter itself but purchases them, right?

Well George, if you want to take my words that literally, then dark is perhaps not the most accurate word, but compared to the surrounding hotspot is is definitely dark.

BTW I invite you to put a luxV in a smooth reflector and even you would agree that the center is DARK, not pitch black but in the sense of being compared to the rest of the beam. I tried that and did not like what I saw.

If youy have seen a properly focused LuxV with a smooth reflector, ie its real image, you would appreciate the job SF did a lot more. In fact the only way to completely eleminate the dim center is by either use aggressive orange peel(which reduces throw) or use a large reflector to focus the image much smaller, which would be horendous for EDCing.

grnamin said:

.... Get a latest generation KL1, swap out the optic with a McR20 reflector, change out the convex lens with a UCL lens and you're golden. You can even have the option of swapping out the LED for a premium U-binned Lux III.

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Whoa, whoa. Wait minute. You can do that? Whats involved? What type a beam does it make? Nice tight hotspot? or a floodie? I like throw myself. But I like reflectored LEDs' that have throw. I have a new black HA KL1 head on my E2D and would love to find out more about that. Links?

Is the KL1 head hard to get open? I also have a TXOH 3W emitter sitting here that I was going to put in a 3W BOG LED drop in.

Please, tell me more!

KDOG3 said:

Whoa, whoa. Wait minute. You can do that? Whats involved? What type a beam does it make? Nice tight hotspot? or a floodie? I like throw myself. But I like reflectored LEDs' that have throw. I have a new black HA KL1 head on my E2D and would love to find out more about that. Links?

Is the KL1 head hard to get open? I also have a TXOH 3W emitter sitting here that I was going to put in a 3W BOG LED drop in.

Please, tell me more!

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KD0G3, check this out:
http://candlepowerforums.com/vb/showthread.php?t=120984

Slightly off topic, but maybe not as much as I think. I don't have an L4, but I do have a U2. It had a bad donut, so I sent it back. The replacement has a slight donut. It's not very noticeable, but it is still there.

I think this is par for the course. Lux V lights tend to have donuts. Maybe 10% of them have a donut so slight as to seem imperceptible. I'd wager 20% ~ 30% have really bad ones.

Good luck.

I remember when the L4 first came out about 3 years ago. The two I owned didn't have donuts. There didn't seem to be any talk here about donuts on SF lights until the U2 came out. From then on, even the L4s started having donuts. I don't know what changed (if any) in SF's manufacturing starndards.

grnamin said:

KD0G3, check this out:
http://candlepowerforums.com/vb/showthread.php?t=120984

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Oh boy. I didn't need to see that! Something to consider. Is it hard to put it back to stock if you want?

So wait a minute, if your just going to take out the optics and replace the lens, do you take it apart in the middle or take out the guts as you showed in that thread?

Also how would you describe the hotspot with the modded lens, tight like a P60 or broad like a L4?

How would the throw compare between the modded KL1 and the stock KL1?

One more question, is the 22.8mm Longbow UCL required or will the "plain" 22.8mm lens work just as good?

KDOG3 said:

So wait a minute, if your just going to take out the optics and replace the lens, do you take it apart in the middle or take out the guts as you showed in that thread?

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You take it apart in the middle, but when you open the only bezel junction, you expose the LED holder/heat sink. You then need to twist that open and out in order to expose the optic.

Also how would you describe the hotspot with the modded lens, tight like a P60 or broad like a L4?

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It's a combination of a really good spot with good sidespill. Less broad than an L4, less spot than a KL1, but the best of both worlds.

One more question, is the 22.8mm Longbow UCL required or will the "plain" 22.8mm lens work just as good?

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The plain one is exactly the same as the Longbow version. Only difference is that the Longbow version comes with an O-ring. It's not hard to put the optic back. Just make sure you keep all the parts.