-Thank you Davidef I appreciate the reply and link to the mathematical calculations and associated theory,I am sure this info is very helpfull for many.
Unfortunately I flunked math (not really) but I am more of a real world scenario kind of guy ,trial and error as opposed to math and theory, as many things in life have had millions spent to solve in a lab, and abandoned later due to things not working in a real live Scenario.
So what i am proposing is you and another light geek like yourself (or perhaps a grumbling spouse asking why?) go outside to a football field ,a open road ,a deserted landscape, measure off x amount of meters from a vertical surface and you …at one end and geek friend at the other with a tape measure and light meter and record the data of the beam falling on the vertical flat surface.
the main reason for this approach is that
A This is the actual fact of the matter, there in front of you to see ,no excuses no regrets.
B A person may then make adjustments to focal length of source to reflector ,or optics ,and try again to achieve hopefully better results.
C Existing production torches may be proven or dis-proved on this data
D Modders may then have a baseline to work from.

I hope some of you may agree this would be very helpfull data for all of us,so let me know what your thoughts and suggestions are.

Thanks