Turning aspheric lenses? (video inside)

[PEU]

Do we have a resident expert in optics?

Im doing some experiments with the CNC Lathe and tought it would be interesting to machine an aspheric lens. After googling for a while I found no sources explaining how to machine one. Wikipedia says that aspheric lenses do not have a formula to define them, so my question is:

How do I draw a profile for an aspheric lens?

Here is a video I made while machining an hemi-sphere in acrylic, turning it into a nice map reader

http://video.google.com/videoplay?docid=-6338999051161832573&hl=en


Pablo

 

[LukeA]

It's a parabola. The more pronounced the shape, the shorter the FL. I'd ask Ra about anything more specific than that.

 

[greenLED]

Pablo, I remember somebody posting about making their own glass optics a while back, but I can't remember who it was. Part of the post said they couldn't be made too big because of the weight. maybe this will juggle somebody else's memory.

 

[LukeA]

Pablo, I remember somebody posting about making their own glass optics a while back, but I can't remember who it was. Part of the post said they couldn't be made too big because of the weight. maybe this will juggle somebody else's memory.

That was Ra making his own 50mm TIR optic.

A 50mm or larger aspheric is plausible to make out of acrylic though.