Please excuse my ignorance as I am new to lights of this sort of power, I have a question regarding an artifact/colour spot within the spot part of the beam on my torch.
I purchased a Manker U23 cool white and have noticed something strange with the beam, I have attached an image below.
I tried my best to capture what I see with the naked eye but this is very hard to replicate. I am seeing a blue dot in the centre of the spot light, It is most apparent at 5/10 meters against plane background.
Just after some advice as to what it is, an issue? normal with this led?
I bought one in warm white and it does the same thing. So I have a warm beam with an annoying blue spot in the middle. Light never should have made it through QC with artifacts like this. Too pricey for shipping back to China, so stuck with it.
When out in the woods with it on a tactical dog walk (ha!) it didn’t prove to be too much of a problem. It has knocked my opinion of manker light down a couple of notches though…
I have a Manker T02 light and it produces the exact same dark spot in the center of the beam.
I have a U23 on order, but won’t receive it for at least another week.
I’m pretty sure the solution is to slice off the dome, though I’ve destroyed a couple of lights learning to take a soldering iron to them that i’m not going to make the attempt.
The spot is coming from color shift in the side spill of the led being reflected and focused to the center point it appears, covering the center of the beam doesn’t lessen it.
So in this instance this is considered a defect with the light then? Its not like the torch does not work or anything I just cant understand why they would sell these lights if the have a defect straight of the shelf.
Take a look at the LED with the light off. See those lines running through it? The XHP50 is basically 4 emitters placed in the space of one, and those lines and the gaps between them. Because of how it interacts with a reflector some of them can create that “doughnut hole” as its called in the center of the beam.
Not a defect, just a poor design choice if they have a smooth reflector instead of orange peel texture.
Even my Neutral White Catapult V6 has a very subtle but coolish spot in the middle of its hotspot like what’s in the picture. It isn’t as defined nor as dim as the one there, but if you were to look hard enough on a wall, you will see it.
I’m thinking it’s the nature of wide and shallow reflectors with smaller LEDs. If the LED is too small in a wide and shallow reflector, you will get a donut hole hotspot. Corona will be very minimal though. 50.2 is a large LED though, so it might not be this.
Some of that can be from the center point between the 4 dies on the XHP50.2 though, but the separation between the dies is far less than the original XHP50, and even the XHP35 in my V6 exhibits that to a small extent.
Definitely not a donut hole, I have one xhp50 that shows a donut hole (nitecore ea81). I’ve got lights that have some artifacts, my thrunite tn35 has a small center artifact which you can see a wall but is unnoticible when in use (mtg2, love this light), the blf gt-mini I have has a dim yellow center point in the hotspot, which I attribute to it being designed to be the mini-me to the blf gt70 I have (it’s so tiny it’s cute). have an old ultrafire with a 3000k mc-e which had a huge donut hole until i sanded down the reflector… All of these I don’t have a problem with. On the U23 warm white it’s the most annoying artifact i’ve seen, with a warm white beam with a bright blue spot in the middle, Probably not as noticible on the cool white one. Not making a stink about it, it does its job outdoors (definitely can see the blue spot when aiming at something, like one of my dogs, or something more or less uniform). I did email Manker about it and they replyed saying that it’s normal, but that being said, had I known how severe it was I wouldn’t have bought the light. It’s a new light and there weren’t any reviews on it, and i’ll use it in rotation with my 120ish other lights…
BTW my neutral catapult v6 has no artifact in the center of the beam. Amazing little light.
That’s due to the combination of the XHP50.2 with a smooth reflector.
The problem was even worse in the first gen. XHP emitters that needed an orange peel reflector in order to diffuse the hotspot and hide the inner blue/violet circle.
There’s supposed to be no donut in new 50.2 since there’s phosphor in the dome IIRC, but I had the EXACT same thing happen in a single emitter XP-G3 light. I think its a tint shift characteristic of “flip chip” emitters like these two. Hard to tell from the pics that its just blue rather than a dimmer spot but I almost guarantee that’s what’s going on.
My $0.02 throw some DC Fix or other diffusion film on the lens and smooth out the beam, or learn to live with it as is.
Yup, that makes sense, my other xhp 50’s / xhp 50.2’s have orange peel reflectors which produce great beams. Perhaps Manker will update the light with an OP reflector that may be orderable.
All of the quad die emitters do this tonsome extent with a smooth reflector. It’s more noticable with a XHP50 or XHP70 (even the 50/70.2 versions).
Best i can say is learn to live with it or try to fine a slighly OP reflector to swap.
Thank you for the reply’s guys, All good information. Its a shame that it does this because apart from this the light really is perfect for me love the form factor and so on.
Not a defect. Remember the way an LED works. It has a base layer that emits blue or UV photons. On top of that is a blob of chemicals that absorb the energy of those photons and re-emit slightly lower-energy photons. But some of the blue squirts out the side and goes to the reflector.
Received my Manker U23 today. It does have the blue dot in the center of the beam. I just think of it as my aiming point . I got the neutral version and the LED is a nice, orangish warm color. I like it a lot. Unfortunately, my light is defective. Moonlight, low, and medium work fine, but high and turbo just make a dim flicker. Cleaned the springs and tailcap and tried my Keeppower UH2652 and LiitoKala Lii-50A cells but no change. I suspect a bad contact at the driver, but the battery tube is glued into the head so I can’t access the driver.
I’m contacting HKEquipment, the seller, to see about a replacement.
. I got the neutral version and the LED is a nice, orangish warm color. I like it a lot. Unfortunately, my light is defective. Moonlight, low, and medium work fine, but high and turbo just make a dim flicker. Cleaned the springs and tailcap and tried my Keeppower UH2652 and LiitoKala Lii-50A cells but no change. I suspect a bad contact at the driver, but the battery tube is glued into the head so I can’t access the driver.