Sold/Expired Concave Lens for Small Flashlight

About to buy a Fenix L0D CE flashlight, but a spot of light doesn't suit. Need a more spread beam.

So looking to replace the lens with a one-sided concave one. ~12mm, say about 4 diopter. I may also be buying a L1D CE, and so will need a concave lens for that as well, ~18mm.

If it is not possible to remove the lens due to the construction of the head, I'd glue the concave over the factory lens.

Does anyone know of a good source for optical grade lenses? Ideally it should have an anti-reflective coating, and be of high-grade media like sapphire, but this isn't critical. Also, recommendations for glue? Cyanoacrylate?

Re: Convex Lens for Small Flashlight

Don't have a measurement, but how about the lens off one of the new model Dorcy 1AAA's? It would have to be cut out of the plastic piece of which it is a part, but it might work.

Any idea whether it's glass? Usually it's not, on flashlights.

Needs to be glass, due to the heat in this flamethrower.

Here is an 18.5mm convex lens

http://www.surplusshed.com/pages/item/pl1007.html

Thanks.

They also have a concave one. Doesn't say how thick it is, nor whether it's glass or not. At that price, gotta be glass tho.

BK7 is crown glass.

I have ordered several lenses from them and they are top notch.

Ray

Hi, the part number of this item is 01 LPX 049, see the pdf here

Good to know Raybo, thanks.

Flex76 thanks, but that lens is convex. I must have concave, as I need to spread the light. I want something more like a floodlight, not a spotlight. They do have concaves on that site apparently. Looks like I've found my source.

Hey, nice thread, great sites too !

I'm looking for domed-lenses, which do not affect the beam, or which could tighten the beam, not give it a flood.

I like the KL1 lens, it's domed, and I use it for my A1 head also.
It does not affect the beam, it's about 2~3mm thick...
(here: https://www.candlepowerforums.com/threads/152369)

What do I need to look for ?

A domed lens will always affect the beam. By 'domed' it sounds like you mean a 'plano-convex', which is flat on one side and positive domed on the other. Plano-convex and biconvex (domed both sides) will always narrow the beam.

With the reflector and LED you already have, with this lens you may end up with a point of light that will start paper on fire. So you'd better try your setup and see how you like just the straight beam first. If you still want a domed lens, start with the site Raybo gave us, and search for your diameter in 'plano-convex'.

Seems like you're running some hot lamps, so the lens you put in there must be glass. Most glass lenses won't reduce the light output noticeably.

:lolsign:
I'm runnin' Cree and SSC emitters, some overdriven.
I have 2 KL2 lenses, both look like the "Meniscus" lens on the link you provided,
meaning they have the curve in the same direction.

What I can tell you from this lens, it does not affect the beam, as I just did
a test to confirm. At least, it is not noticeable at all.

The lens is 3mm thick and 22mm in OD. I think it's hard, it came from a KL1 head.

What I can tell you, is that if I take off my glasses and look into the lens,
I see just as good as with my glasses. (-3)....

Cheers !

Oh, OK. When you say domed, you mean meniscus.

When the back and front of the lens have exactly the same curvature, there is no change in the light, as you say.

bombelman said:

:lolsign:
I'm runnin' Cree and SSC emitters, some overdriven.
I have 2 KL2 lenses, both look like the "Meniscus" lens on the link you provided,
meaning they have the curve in the same direction.

What I can tell you from this lens, it does not affect the beam, as I just did
a test to confirm. At least, it is not noticeable at all.

The lens is 3mm thick and 22mm in OD. I think it's hard, it came from a KL1 head.

What I can tell you, is that if I take off my glasses and look into the lens,
I see just as good as with my glasses. (-3)....

Cheers !

Click to expand...

bombleman,

If you want to run your light without a reflector you could try a lens with a slight aspherical curve, the beam might not be as pretty as a reflector but you will get some good throw.

Ray

No, I really like the reflector and dislike optics.

I just like the 3mm thick domed lens from the KL1, I want to try it in different lights too.

Found the answer. Don Mc tells me about a diffusion grating from Luminit. Very efficient, although I may choose their fresnel instead.

Whups, they're $175 for a 3/4" disc.