How to Calculate Relative Throw and Flood With Excel Formulas

Under construction to make more user friendly :slight_smile:

luvlites, that is very technical and I really appreciate your sharing here.
This is in another dimension besides purchasing and modifying or playing with flash light.
For SC52, flux increase from 280lm to 900lm only increase throw from 80m to 144m.
Your data is quite accurate. I increase my TN31 current from 3.5A to 4.2A, I estimated increase of 100 lumens for flux.
Based on your throw factor of 18.88 for TN31, that will increase intensity by 11kcd. My modified TN31 does increase intensity by about 10kcd.

Thanks again.

Thanks for the work, those are nice parameters to consider. There are however two sides on doing the maths on flashlights. The scientist in me is very satisfied that things like throw and lumens of a mod or a new light can be quite nicely predicted from reflector type/size, type of led and current (there just are no big surprises in the real world). On the other hand, the romantic in me is disappointed that (there just are no big surprises in the real world)

I’ll be honest the maths gets a little beyond me.

But I do personally find it interesting in what is considered “throw” or “flood”. Such as how do you define these?

One could argue that throw and flood are the nature of beam, not the actual figures. An incan Mini Maglite can be focused into a tight beam and is very “throwy” in my opinion. But evidently it has far less beam distance than something like a Sky Ray King.

That same is true of flood, is it about how wide the entire beam is, as in how wide an area is illuminated in total, regardless of brightness. Or does it means specifically to either the spill beam or the hot spot? Or is it about how even the transition is between the two?

Yes, and the nature of a beam can be characterized fairly well by a light’s luminous flux in lumens and luminous intensity in candela together, which are the two inputs for each metric.

Thank you for the work behind this, it enables one to more closely estimate the fruits of the labor when making a light.

BUT, it also dispells some of the “magic” in modifying a light. As djozz says, it kills the romance. So, kudo’s to you and the good Dr. for taking all the fun out of it and making it purely a science lesson.

I can now throw my 40+ lights away and just keep the 3 radically different ones, as the science shows they all do the same thing, make light in a cone shaped pattern. :wink:

Eureka! I’m cured! :stuck_out_tongue:

For some (geeks), this adds to the fun :slight_smile:

More calculator time…

For serious modders, we want more light time instead :wink: lol

Thanks for all your efforts,very detailed and deep,some a bit over my head!! lol!

Would this be an accurate/simple way to define “Throw Factor”as it is used in the most efficient and productive way?

The ability for a light to get the most amount of throw with the least amount of lumens?
EX: My OSTS TN31mb-470Kcd, 44.6 Throw Factor

I think there is a better way to say it but it is not coming to me now!



Thanks for the work done here. WAY over my head, but I am sure some will understand and use it.

I would imagine from this, you could formulate the exact reflector needed to be built, for each led, like XM-L2, XP-G2, MT-G2 and then send that on to all of the dealers, so they can start making the ultimate throwers?

Depth of the reflector seat, to the led would probably also be needed, since reflectors have to be focused, but I imagine those numbers could be done too?

It would be nice if all the manufacturers and dealers could just pick the needed reflector for a certain led, to produce a maximum thrower, or a maximum flooder.

Me, I'll just keep picking up whatever I got laying around. Numbers fry my little pea brain.