Mod hotspot to get smooth transition to spill?

Flashlight Modding and DIY Parts
1

I was looking for suggestions on how to get one of my lights with a relatively defined hotspot to have a slightly larger and smoother transition into the spill without loosing too much of the throw.

I read somewhere that some people use frosted tape or similar on the lens, while someone else uses a touch of clearcoat sprayed onto the reflector. I am hoping to get a beam profile somewhere between my Streamlight Protac HL4 (uses frosted lens) and Klarus XT21X (uses RP reflector). Preference to the HL4 beam profile.

I am thinking about trying this on my Streamlight HL-X. Obviously tracking down wider frosted tape would be easier and not permanent. Anyone have experience with this type of thing? I’m afraid if I try the clearcoat mod that if I don’t like it or mess up, I’m stuck with it.

2

Wellp, they’re kinda mutually exclusive. You wanna blur the beam, you’ll lose some throw.

So either stick-on film that you can peel off, or nonsticky film that you stick between glass and reflector. Both are reversible.

3

If you’re not happy with the beam, then I would just go with a permanent solution and frost the lens. It’s fairly easy to frost using sandpaper assuming it’s not an AR lens. Depending on the sandpaper grit, you can lightly frost the lens or go heavy.

Or if you want a non-permanent mod, you can try this: DC-Fix Diffusion Film Sale.

4

I use a diffusive film from a broken laptop screen. It makes the beam smooth and removes all artifacts, but the increase in spill is minimal. Also reduces output about 10 to 15 percent.

5

Thanks all for the suggestions! I’ll try to test some of the suggestions when I have time.

Would it make any difference if I placed a frost on the inside of the lens vs the outside? I think Malkoff suggests placing theirs on the inside IIRC. I’ve played around with some frosted tape and privacy film on the outside of an ET, but not on the inside.

6

I have the 1% diffuser on my Malkoff 18650XT head behind the lens, cleaned up the beam at the expense of candela of course.
What has me curious is they made a nice head with high kcd but a terrible beam using optics, yet we see plenty of other high powered lights work fine with optics.

7

I don’t think it would make a big difference.
I use mine between the glass and the lens in a Convoy s2+.
If you want a big spill with some throw there is a called ultra thin lens. I know that many companies use them, like fenix and wuben. I’ve just ordered a fenix e28r for 35 bucks, just waiting to test it.

8

the reason to put it inside is because diffusion film is plastic, so the lens prevents it being scratched

otoh, I would be afraid to put plastic in your High Powered Thrower, because I fear it gets hot enough to melt plastic. So, just to give yourself an idea, I would just put Scotch Magic matte-finish tape on the outside… leave yourself a handle to peel it off again

I recommend you NOT make any permanent modification to the reflector nor lens. However, you could buy a replacement lens, and experiment frosting it with sandpaper scratches (I suggest 600 grit)

imo, you will soon realize that diffusion robs the light of throw, which defeats its design purpose

as an alternative to trying to change the beam on your tactical light, I suggest you buy a different light, for those times when you want a different beam…

9

Just out of curiosity, does the Malkoff design allow easy access to the reflector? I noticed on my HLX that if the head is tightened down all the way it distorts the hotspot. I have it out maybe 15 degrees to get the hotspot how I think it’s supposed to be.

10

I’ve accumulated quite a few lights over the last few months chasing down size, UI, beam profile, runtime, etc. Although my EDC is usually floody, I’m playing around with finding a secondary for gerenal outdoors under 100 yards. My favorite beam profile for this is on my HL4, which uses a frosted optic from the factory. I’m pretty happy with the HLX and P20i size, UI, overall design, and runtimes… I would just be happier with that HL4 beam profile, so I thought I’d spend a little time seeing if I can get something similar from the HLX or P20i. If that means testing out some tape on the lens, it’s easy enough and reversible.

I have some diffuser material at one of my job sites I am going to cut down. Maybe try to make a donut hole diffuser if I can keep my lines straight with an exacto knife.

11

Not all models but the 18650XT head they allowed it for diffuser changes.

12

DC Fix is pretty good stuff and does a nice job on many lights. Ultimately the reflector shape and combo of emitter and how they're mounted is going to override minor corrections like this, so if the pattern transition is really abrupt you aren't going to be able to totally smooth it out without getting drastic (and losing a lot of light and/or throw in the process). I think I got my DC Fix from Vinh at Skylumens for about five bucks which is enough to do a few or many lights depending on size. I don't know what light we're talking about here or the size of it, but there might be the option of swapping the reflector for either a different one or with a plastic optic where you can pick what you like (Kaidomain has lots of these...and they're on Aliexpress as "LHT Flashlight Store" or something like that).

Personally I think scotch tape was a fantastic invention but it never did much good for me with flashlights. If you spray or treat the reflector that's a permanent change so consider that carefully because you won't be able to return it to its as-new state without ruining the surface. I'm going to have to look more closely at monitor films. I did save a piece from one that wouldn't be good for flashlights but it's a neat material to keep around for whatever. We toss or donate a fair amount of monitors at work every year or three and usually it's a spread of brands and types.

13

Just an update… I ended up using some DC-fix from HD (Sand IIRC). It seems to increase the spill area as well as smooth out the hot spot transition. I liked it enough to use it on a few of my EDC lights.