Donut hole on Acebeam K75 and K65GT

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Giancarlo
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Donut hole on Acebeam K75 and K65GT

I just got the new Acebeam K65GT and noticed the typical donut hole in the hotspot. Has anyone else noticed the same flaw in this flashlight or even in the new Acebeam K75?

Yokiamy
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Its not a flaw, just try it at a larger distance instead of 1 or 2m

Giancarlo
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Yokiamy wrote:
Its not a flaw, just try it at a larger distance instead of 1 or 2m

By far I tried the light up to 200-300m and the hole was visible. I consider it a flaw as it is quite annoying. It means that the beam is not well focused. Acebeam should move the led back or forward respect the bezel or maybe the bezel hole is too large.
Lightbringer
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Giancarlo wrote:
By far I tried the light up to 200-300m and the hole was visible. I consider it a flaw as it is quite annoying. It means that the beam is not well focused. Acebeam should move the led back or forward respect the bezel or maybe the bezel hole is too large.

Actually, that means the LED is perfectly centered and focused in the reflector. You’d have to defocus it slightly to get rid of the doughnut hole and blur the hotspot.

Think about it. Only side-light that hits the reflector and gets thrown forward ends up in the hotsspot. Where the LED is, well, only directly straight-out light (“spill” that just happens to be aimed straight out) fills that hole, whereas everything else either hits the reflector and ends up in the hotspot, or misses the reflector and ends up as spill. (Exaggerate the hole where the LED sits, to where the reflector is only a ring, and trace out the rays.)

All my best throwers, GTminis, GTmicro (at least my CW one), P30, etc., all have at the very least a dimmer and often bluer “hole” in the hotspot, albeit very faint.

Sometimes it’s almost a pinhole, other times spread out in the hotspot, but it’s almost always there.

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Giancarlo
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Lightbringer wrote:
Giancarlo wrote:
By far I tried the light up to 200-300m and the hole was visible. I consider it a flaw as it is quite annoying. It means that the beam is not well focused. Acebeam should move the led back or forward respect the bezel or maybe the bezel hole is too large.

Actually, that means the LED is perfectly centered and focused in the reflector. You’d have to defocus it slightly to get rid of the doughnut hole and blur the hotspot.

Think about it. Only side-light that hits the reflector and gets thrown forward ends up in the hotsspot. Where the LED is, well, only directly straight-out light (“spill” that just happens to be aimed straight out) fills that hole, whereas everything else either hits the reflector and ends up in the hotspot, or misses the reflector and ends up as spill. (Exaggerate the hole where the LED sits, to where the reflector is only a ring, and trace out the rays.)

All my best throwers, Geminis, GTmicro (at least my CW one), P30, etc., all have at the very least a dimmer and often bluer “hole” in the hotspot, albeit very faint.

Sometimes it’s almost a pinhole, other times spread out in the hotspot, but it’s almost always there.

You are right. The presence of the hole means just that the beam is perfectly focused. Yet I have many big throwers like Astrolux MF04, MF04S and BLF-GTvn with no doughnut hole, and the hotspot doesn’t look unfocused. Well, I would prefer the beam to be a bit unfocused so to remove the hole and get a larger hotspot, even though I think I would lose a little throw.

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Sometimes just a sliver of kapton tape between reflector and star will do the trick. Else an OP reflector.

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Giancarlo
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Lightbringer wrote:
Sometimes just a sliver of Kapton tape between reflector and star will do the trick. Else an OP reflector.

I like the OP reflectors as they produce a nice hotspot but using them in a thrower would be nonsense as they shorten the beam distance.

Yokiamy
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Giancarlo wrote:
Lightbringer wrote:
Sometimes just a sliver of Kapton tape between reflector and star will do the trick. Else an OP reflector.

I like the OP reflectors as they produce a nice hotspot but using them in a thrower would be nonsense as they shorten the beam distance.

That’s actually a misunderstanding, the losses with OP are minimal, only a few percent

Giancarlo
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Yokiamy wrote:
Giancarlo wrote:
Lightbringer wrote:
Sometimes just a sliver of Kapton tape between reflector and star will do the trick. Else an OP reflector.

I like the OP reflectors as they produce a nice hotspot but using them in a thrower would be nonsense as they shorten the beam distance.

That’s actually a misunderstanding, the losses with OP are minimal, only a few percents

Did you never see a thrower with an OP reflector?

KawiBoy1428
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Yokiamy wrote:
Giancarlo wrote:
Lightbringer wrote:
Sometimes just a sliver of Kapton tape between reflector and star will do the trick. Else an OP reflector.

I like the OP reflectors as they produce a nice hotspot but using them in a thrower would be nonsense as they shorten the beam distance.

That’s actually a misunderstanding, the losses with OP are minimal, only a few percent


Depends on the quality of the finish…some Heavy OP Dull finish kills throw… Light OP with a High Finish not so much…same with Smooth Reflectors…

KB1428 “Live Life WOT

Giancarlo
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KawiBoy1428 wrote:
Yokiamy wrote:
Giancarlo wrote:
Lightbringer wrote:
Sometimes just a sliver of Kapton tape between reflector and star will do the trick. Else an OP reflector.

I like the OP reflectors as they produce a nice hotspot but using them in a thrower would be nonsense as they shorten the beam distance.

That’s actually a misunderstanding, the losses with OP are minimal, only a few percent


Depends on the quality of the finish…some Heavy OP Dull finish kills throw… Light OP with a High Finish not so much…same with Smooth Reflectors…

Did you never see a thrower with an OP reflector?
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No holes on my K75 and K65GT. Can you post a beamshot?

As I said before, I never repeat myself.