Weird beam of new Convoy MC21C

Hello all flasholics,

I have more than 30 flashlights and the last ones are still on their way :laughing: One of my last throwers which I bought is a Convoy MC21C GT-FC40 which has a strange yellowish and darker hotspot. It looks like the LED is not in focal point. I have over 15 throwers and this is the first one with such a flaw. I also have another flashlight with a GT-FC40 Convoy M3-C which is floodier but the hotspot is clear. What do you think?

Please enjoy your time here, Tomahawk!
Wow, that is weird.
I don’t know anything about the GT-FC40 so I wouldn’t know what to expect.

Have you seen the movie Bone Tomahawk?
It’s a pretty good horror/western film, if you like that sort of thing.

Looks like xhp70 to me

Thank you for welcoming me to BLF Raccon. I like famous axes and other weapons more than western movies themselves.

M3-C has no yellow-green hue, just pure white hotspot. If I stand only 1m away from the wall, the hotspot is fine. Maybe I should replace the reflector with an orange peel? I also compared the LEDs of both flashlights and they look the same.

All my flashlights have the brightest spot in the centre itself. This one has a bright donut. :thinking:

I recently had the opposite issue on a M21A.
Try raising the reflector(put layers of tape below the gasket), and if that makes it worse, then lower the reflector (sand the gasket).
You want the beam to be colinear, not convergent or divergent. Yours looks possibly divergent.

This is likely an issue with uneven phosphor distribution. Turn on moonlight and look directly at the LED. (Or use a convex lens to project an image of the LED on a white surface.) Does the center of the LED look dimmer and more yellow-green than the boundary?

If this is indeed the issue then there is no easy fix. Maybe some diffusion film will alleviate things, but it’s better to replace the LED entirely.

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I’m not seeing a Convoy model with that name anywhere on Convoy’s site. Do you mean M21C (rather than MC21C)?

I also have a flashlight with such a ‘egg yolk hotspot’ like in your photo. (In my case it’s in a Convoy S2+ with a SFQ65 LED in it.)

I found a post here on BLF from member @djozz , who also had this issue and in the end he managed to solve the issue by positioning the LED further/higher in the reflector. I believe he removed the gasket/centering ring and even reemed part of the reflector (hole) to get the LED higher up in there. (Unfortunately I can’t find that post anymore.)

I’ve been trying to fix my ‘egg yolk hotspot’ in more or less the same way, by sanding down the centering ring really thin, but that alone wasn’t enough. I also grinded down the reflector cup partially, but now I’m running into clearence issues with the MCPCB wires, so I have to file down other parts of the outside/backside of the reflector to get it to fit, so I’m not yet sure if it will solve the yellow hotspot in my case.

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Check the LED’s phosphor distribution before trying anything else–no amount of focus adjusting can fix this (source):

3 Thanks

My typo, it’s an M21C. Sorry about that.
I will try to project the LED on the wall using a magnificent lens.
But the question is, is this flaw enough to make a claim?

I’m not sure, but it’s worth a try! Send the photo you get to the seller to support your claim.

I see two cracks in the wall so it’s clearly illuminating them. The yellow spot looks very well centered to me. What claim are you trying to make? Not every LED is going to work perfect if there is such a thing in every light. Convoy probably offers more lights with more LED choices than anybody else. They are not all going to be perfect. Again assuming there is such a thing.

I also think that’s not enough to complain about. I have checked the LED with a welding mask glass and a magnifier lens and
it is perfect. Projection on the wall with a help of magnifier lens doesn’t work. If it was an Acebeam or a similarly good brand (and price) then I would have make a claim. So I’ll play around a bit with a orange pell reflector like the M3-C has. I don’t want to look at my collection and say, well, that’s a lemon. It will be removed if changing of reflector doesn’t help.

I think I have checked the LED before and seem to remember the phosphor seemed fine/even, but I will check again.

I have several spare S2+ reflectors laying around, so I just decided to give it a try and see if it would have any impact. And it also keeps me busy, so that’s a plus too! :grin: