Where to buy glass aspheric lenses?

Looking for an online store with worldwide shipping where I can get some glass aspheric lenses, similar to those in sipik type zoomies but made of glass. I know they exist because On the road i3 light has one

They tend to be rather pricey, but can be found at Edmund Optics and Thorlabs.

I couldn't find any similar to the Sipik size with the flange like the SK68/98 lights have. This is something I had been looking for, myself, as I have several SK68 and SK98 lights, now. I've sort of stopped looking since I've come to appreciate the gradual light falloff or vignetting of my other flashlights.

I have bought some 40-44mm borosilicate aspherics with reflectors and mounts with various focal lengths for less than $3 with shipping on the auction site. I've seen some 54mm lenses for not much more, and some 77mm lenses for less than $10, with reflector and mount. I have a feeling all these are too large for what you're wanting to do.

Thorlabs has some around the right size, but not precisely the same size as either of the two SK68 style lights I have(which do not work with each other's lenses). Thor has a 20mm, and my SK68 lights have 22ish to 23mm lenses(with flange). My SK98 lights use a 26mm lens. They do have a 25mm lens, so that theoretically might be close enough. But from what I can tell, the Thorelabs lenses do not have a flange, so mounting in an existing light might require some fabrication/modification. Could be as simple as an o-ring? Just one of the Thorelabs lenses would cost more than I've paid for all my SK lights combined, so I've been hesitant to mess with it.

Member AHorton used to sell some that he had made. Prices were very reasonable and lenses are awesome! Is he still around?

DIWdiver said:

Member AHorton used to sell some that he had made. Prices were very reasonable and lenses are awesome! Is he still around?

Click to expand...

Not seen him in a year or so.

Reference link....

https://www.candlepowerforums.com/vb/showthread.php?308032-Ahorton-s-sales-(Lenses-headlamps-)

Illumn has the Ahorton lens and spacer

Thank you gentlemen! I think in the end of the day I would try one of the high end coated lenses from edmunds or thorlab, but at the moment I have found some on aliexpress for about a dollar each, so I will give them a try first.

The plan is to fit a lens to a 1" head, either a e1 bezel clone from lumens factory, or mac triedc, or an rrt01, so I am prepared to trimming the lens (I can do that) and using some sort of fixture. I am sure I will need one at least for setting the lens at the right distance from the LED to achieve ~90deg beam opening

One thing I learned about lenses is that a very short focal length is good. Say you have a 1" diameter lens with 1" focal length. You put the LED 1" away. A pretty good portion of the light from the LED will hit the lens. But if the lens has a 3" focal length, and the LED is 3" away, far less light from the LED will hit the lens.

Both lenses may produce a beautiful tight beam, but the one with the shorter focal length will be far brighter. The beauty of the AHorton lenses is that the focal length is VERY short. As I recall, it's a bit less than the diameter of the lens.

DIWdiver said:

One thing I learned about lenses is that a very short focal length is good. Say you have a 1" diameter lens with 1" focal length. You put the LED 1" away. A pretty good portion of the light from the LED will hit the lens. But if the lens has a 3" focal length, and the LED is 3" away, far less light from the LED will hit the lens.

Both lenses may produce a beautiful tight beam, but the one with the shorter focal length will be far brighter. The beauty of the AHorton lenses is that the focal length is VERY short. As I recall, it's a bit less than the diameter of the lens.

Click to expand...

That is certainly true.

But in my case, I plan to do the opposite thing: I will fix the lens as close to the LED as I can to get as broad beam as possible. The need for a glass lens is partially related to this as a plastic lens is prone to fogging if placed close to the hot surface of the LED.

One may ask, why not just a mule? Two things:
1. A mule beam is too wide so I have found it to be inconvenient for night time, when the light would hit too many eyes.
2. An aspherical makes considerably more uniform beam across the 90 spot than a mule.

Maybe Optolife will have something for you?

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