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Hello all, I have browsed this site on many occasions and decided to join now, and share in all the knowledge.
I have been a lighting geek for many years and have owned countless flashlights, some stage lights, projectors, a few lasers and a ww2 searchlight.
I have always been most interested in the nature of “beams” weather they be God rays from the sun, a lighthouse, or stage lights at a Pink Floyd concert, and I think it is totally amazing the innovations which have come from the led revolution and by the members of this site and diy’ers all over the globe,so congrats !

My question to get things rolling is…

Has anyone set up a standardized test of distance/throw and beam power combined?
Something like “at 300 meters , the beam spot, (or diameter) equals x Feet/inches wide, and the intensity measured on a light meter at that distance equals x when the meter is placed directly in the beam path.

If so I would like the link to the instructions for a test of this type, or otherwise I think it would be great to create one, with suggestions from all of you,of course.

So let me know your thoughts, thanks

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The standard calculation for throw has beam intensity included in it. So, the throw is the measured distance at which the light intensity becomes X amount. Beam angle can also be measured, but not too precisely. I guess you can get really close to calculating supposed beam width at a specific distance, based on the beam angle, but it won’t be very accurate, I think.

EDIT: Here’s an old thread that can help you some. LINK

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-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

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Well… I have given this idea 2 weeks to incubate, and I must say I had hoped someone would have at least been able to provide a little bit of data… of some form, to kick off a compilation list, cant really figure it?

I see lots of threads with claims… and beam shots , and no real data to backup the lumens/candela/mcd/etc.
of the actual end product of the beam, at the throwing end point.
I think this exercise would be comparable to the use of an integrating sphere in a lab ,when used to measure total output of a source ,but tailored more to the interests of people of this forum?

Please mind you , I have much respect and admiration for the innovation and intensive data which has been produced by many on this site.

So please if you may…