Flood Vs throw graph

I'm tired of seeing reviews that say a flashlight has "a good mix of throw and flood" I'm sure I'm not the first one to think of this and if so why isn't it being used? I propose that all flashlight reviews use a Lux/degree's graph. This clearly shows the flood/throw mix.

I've prepared a simple and dodgy graph to show my point (there would be many more points of measurement to illustrate the flood/throw of a flashlight). This would also allow discussion of the best throw/flood's such as preferences for a tight spot or a very gradual spotlight without just saying "has good flood and throw"

That would be a beam profile. I've seen some in the past.

That's brilliant, i just google'd that and see other people using them. Why doesn't everyone use them?

(i understand that the profile changes as you go further away from the torch but its still better than "good throw vs flood")

jeowf said:

Why doesn't everyone use them?

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Because pi**ing contests organized by the "throw uber alles" camp are about lux @ 0 degrees, and the largest number wins.

Comparing beam profiles is more difficult and the winner not so obvious.

Nap.

Using a polar graph format (vs. cartesian format) would more closely resemble the light's pattern.

gurpreet.dhal said:

As a newbie here... isnt throw much better then flood? I may be wrong

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It greatly varies depending on your intended use of the light.

gurpreet.dhal said:

As a newbie here... isnt throw much better then flood? I may be wrong

Click to expand...

Very generally, you'll usually want throw (with decent spill) for outdoors, when subjects are more likely to be far away. Indoors, you'll usually want more flood, because too much throw can make the center of the beam difficult to look at.

For example, I just can't use my Sunwayman V20C indoors on high (400+ lumens) because the spot is too bright to look at, and the V20C isn't even an extreme thrower.

Jeowf, you're right on track. Graphs like that are very useful, and I've only seen a handful of them on cpf. That may be because setting up the experiment to take all the necessary data can be pretty time consuming, and a beam shot will yield the same data (albeit less scientific) and is a lot easier to do.

Also, as far as using this as a means to compare throw, I'm not sure if this will necessary show how well one light throws compared to another. I'll have to think on it some more, and try a few tests, but here I my initial thoughts:

Beam profiles like your graph will illustrate will change depending on how far you are measuring from the focal point of the reflector. Because the light is not a point source, but (practically) a point source reflected by a parabolic mirror, the beam profile will change as you move further away. So, while two lights may have very similar beam profiles at 1 meter, if they have differently shaped reflectors, could have very different beam profiles at 10 meters. This means one light is the beter thrower, but that's not obvious until you compare beam profiles at multiple distances.

Does that sound right? Someone correct me if I've gotten mixed up. I'll try to draw a picture that shows what I mean.

Brilliant. I agree that these graphs should be used more often. Much better than people just saying "excellent throw with useable spill", We all define good throw and spill differently. Personally I think of good throw as alot more than most people. With graphs like these we can decide for ourselves if throw and spill is good or not.

However I do see a big flaw with these graphs. They dont take into account how bright the spill is, you could have a light with beam angle of 100 degrees, you might think that means it has good spill. But that spill could have not enough light intensity to be useable.

Think beamshots and lux readings will have to do for now