78 mm aspheric lens!

Any flashlight big enough to put this? or, it is too too too big?


It says is made of glass....

It may fit the TrustFire X6 the head size is 80mm but it will be too big for the Trustfire x7 which has a head size of 78mm.

"GaoPeng silicon K9 glass"... means.... not real glass? (I mean organic)

Woo! I was just about to order the 66mm optic to do some testing with. My ~50mm XR-E/Aspheric mag-mod has lost it's pizzazz. I'm working out a plan for a larger-diameter aspheric thrower and was wishing someone had larger diamater lenses available!

FWIW, surplusshed.com has an assortment of lenses. Located in Pennsylvania.

(And a lot of miscellania, there , too)


I tacked this onto an order to DX I was already making this morning. Now, hopefully DX will be quicker than last time and I won't have to wait two months to get it...

And... in which flashlight are you going to "install" this monster lens?

I'll be experimenting with this lens to determine if it will be suitable for a light. Once I determine that, I'll look into options for fabricating some sort of solution. I have some ideas... Cool

wow, dont forget to upload photos of the final... "result"

I also have some ideas in mind....

Trust me; if my ideas ever come together, I will be posting pics here! If I had access to a lathe, aluminum stock, and a metal shop, it would be a terrible thing!

Waiting for your... "terrible thing".

I will be "investigating" alternate uses for it.........

Well ... this lens is not aspherical. At least, looking on the photos, it doesn't have the aspherical curve. It's just plain spherical lens. This means, it has quite big focal lenght. I did some rough calculations and to focus properly the LED, the lens has to be pulled ~80mm away from the LED. This means, a LOT of light will be wasted and only part (half at best) will go through the lens.

The lenses used in Mag aspheric mods, Tiablo A9, Dereelight DBS, etc., they were all aspherical and they achieved great results due to smaller focal lenght (that means more light from the led passes through the lens). The lenses that DX sells are spherical and the results won't be as good. Though, jf you didn't see what real aspherics can, it might impress you. But remember, to properly focus the LED in this lens, the LED has to be pulled approx. 80mm from the lens. I have no idea what host will allow for this.

a good donor:


Just looking at the curvature suggests a focal length at least as great as the lens diameter.

"Tumbler shaped"? Concavo convex?

Wow! I drive past that place everyday when I drive to work. I always wondered exactly what they had in there.

I got the lens in the mail yesterday. I haven't had time to play with it much, but here's some info...

OD - 77mm

Thickness - ~33mm

Focal length seems to be about 35mm the best I can measure

The lip around the edge of the lens is about 4mm wide

The glass seems nice and clear, but when you look through it, it does have swirls (not unexpected). I took this light outside and used my RC-G2 with the reflector removed to compare against my DX 50mm aspheric and my initial impression is that the 50mm performed better. I'll get my light meter and try to get some more measurable results sometime soon.

Thanks for the update!

I still have not found any suitable body for this monster-optic