Spotlight Optics question!

I am a dentist who loves LED lights!

I am interested in making an improved overhead light for the dental chair (for personal use only.. its just a hobby) - the lights that are currently used produce yellowish light, with far too much flood. I want a light that has perfect spotlight like edges and shaped in a rectangle.

I have messed around with optics before but it was more a trial and error sort of thing. I ordered a bunch of random lenses off dealextreme.com, and using 3 of them got a decent spotlight, though it wasn't perfect.

Could anyone point me in the right direction for a more methodical process of creating a spotlight using lenses? Thanks!

A TIR??? Have you tried messing with the focal length any? Rectangle? I bought a DaZongTong anglelight from Manafont (bad move) that while it worked produced a perfectly square, uniform pattern of light that filled a nice sized area... maybe a quad LED setup with the right TIR can give you what you're looking for.

Sorry, what does TIR stand for??

The best example from recent postings:
http://www.candlepowerforums.com/vb/showthread.php?313013-Just-started-a-dental-flashlight-project

Walterk said:

The best example from recent postings:
http://www.candlepowerforums.com/vb/showthread.php?313013-Just-started-a-dental-flashlight-project

Click to expand...

Just what I was looking for! Thanks!