[Laser] Fresnel lenses etc from Chris Long

[Karel Kulhavy]

> The gain would be much higher for a diffraction limited source like a 
> laser, but the lens would have to be several orders of magnitude more 
> accurate and your bank account would have to = Bill Gates!

You can exactly measure the actual gain for given LED + lens combination
by a free technology measurement device developed specially for this
purpose called Ronja Benchpress:

http://ronja.twibright.com/benchpress/

> Don't take my word for it - read the refs and do the experiments! In this 
> manner, Karel, I have admiration for your experimental efforts. Mike and I 
> are not trying to operate any sort of commercial enterprise so we can't 
> offer to 'merge' with Ronja, but you're welcome to our experimental results.

Ronja is not a commercial enterprise. It's driven by volunteer
donations:
http://ronja.twibright.com/sponsors.php
Some people have also contributed work, instruments or similar:
http://ronja.twibright.com/contrib.php

On the same page you also find my reasoning why Ronja can't be
commercial.

Cl<