Finding small aspherics?

Hopefully this is in the right place (or is there an optics section I haven't seen?).

Does anyone have any recommendations on small aspherical lenses, and where to get them? If possible, under 20 mm dia, for a Cree XRE. So far I've seen these ones at DX, but not much else.

Unfortunately for my project, space is a real limitation, hence the size restriction.

On the other hand, if there's something inherently stupid or impossible with aspherics that small, please say!

I cant really answer your question but I use those DX aspherics.
I glue them to PVC pipe then cut down the OD on the lathe to about 18mm. Then cut the PVC to length and mount it above the XR-E's.

Works well for me. But if you dont have access to a lathe then you could file down the edges of the aspherics to fit. They have a 1mm lip on them.

Edmund Optics has a 15mm for about $30.

http://www.edmundoptics.com/onlinecatalog/displayproduct.cfm?productid=2454

Thanks for the info guys, if worst comes to worst I'll try your suggestion Packhorse. Any other recommendations out there?

Hi TH232,

I've bought 4 of these recently to use in an RC-N3 Q5 from shiningbeam.com.

http://www.surplusshed.com/pages/item/l10085.html

They're plano-convex. I've found that they disperse the beam a little more than your typical Q5 Mag aspheric even when focused to a die shaped projection.

hope this helps!

Cheers!
Sami

Edit: Sorry, I just noted you said "below" 20 mm, for that, I may suggest the following:

http://www.surplusshed.com/pages/item/l10017.html
http://www.surplusshed.com/pages/item/l10141.html

Although to be fair, I think there is a point of diminishing returns with these type of optics. A very small lens may not be able to capture all the light emitted by an LED emitter.

Thanks for the links Sami! Cheap enough for me to buy both those and the DX ones for some experimentation, too.