what makes a flashlight throw.

[MaxaBaker]

[ QUOTE ]
CromagNet said:
Very nicely put Don!

Therefore, since "photons will cross the galaxy if they are not redirected or absorbed by something" we can say that every light has tons of misleading throw but the percieved or "visable throw" is a combination of a light source with the least amount of redirection and absorption loss. A reflector that can focus more photons/water in a tighter beam will generate more visable throw. And we measure that in a standard of LUX. Can we say that LUX numbers compare visable throw for flashlights. Then LUX numbers are influenced by LUMENS if we've determined that LUX is measurement of "visable throw"


[/ QUOTE ]

Oh, I think that hit it on the head. Nicely put CN.

 

[McGizmo]

[ QUOTE ]
....we can say....."visable throw" is a combination of a light source with the least amount of redirection and absorption loss

[/ QUOTE ]

No and yes. In the case of the High Dome Luxeons, the LED has a lambertian distribution which means the light is rather evenly dispersed through 180 degrees of beam angle; wide flood. For throw (illumination of distant target), we need significant redirection of the photons so that they travel to the target and not half of the universe.

The A-3 reflector is based on the same parabolic curve as the A-1's. It is extended which means it is a larger (deeper) section of the same curve and will alter the direction of photons which would have escaped in the unafected "spill" portion of the A-1. I am experimenting with a 45 mm reflector that is just a larger section of the same curve, yet again. In viewing the beams from the A-1, A-3 and now the 45 mm reflector, it looks like the 45mm has a tighter beam than the smaller ones but surprisingly it is the same beam as the smaller ones but with added light to the center which would have been spill, otherwise. In the picture below, the three reflectors on the right are all based on the same reflective curve; merely progressively deeper or taller extensions.

The 45 mm reflector concentrates more of the generated light in a tight beam with a resulting greater intensity of reflected light down range, on target. Now, if the target is a school bus at 50 feet, this reflector is not a good solution! /ubbthreads/images/graemlins/nana.gif

 

[Kiu]

Don,

great pic!
Do you mean there will be Aleph 4 very soon? /ubbthreads/images/graemlins/evilgrin07.gif /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/popcorn.gif

 

[cheesehead]

[ QUOTE ]
thesurefire said:
So if I'm understanding you correctly you are saying Lux matters, but the "measure of total output of light eminating from the source..." Do? Lux and lumens are related, not very closely, but they still are, thus lumens should matter, correct?

Little test: get a 3 and 4 cell maglight. They all should have reflectors that are very close to identical. Get 2 3 cell bulbs. now put 1 in each mag and turn them on. Witch one will throw further? The stock or the overdriven? The overdriven one will I guarantee it. So if lumens don't mater (and by saying lumens don't mater you are implying Lux doesn't matter) please explain to me why the overdriven bulb throws further then the stock bulb.

[/ QUOTE ]

Well, duh, an overdriven bulb will throw farther, it has a higher surface brightness (there's your explanation /ubbthreads/images/graemlins/confused.gif). Same like my Maglite with an overdriven 3D bulb in a 4D body will throw farther than an underdriven Thor at 100 watts.

Again, LUMENS DON'T MATTER!!! And neither does Lux. /ubbthreads/images/graemlins/banghead.gif

 

[Led_Blind]

Oh my..... It is a bit like that /ubbthreads/images/graemlins/icon23.gif

The water spray explanation is probably the simplest way to explain this. The amount of water coming out has an effect on how quickly you will fill that bucket true... but throw is how much of the available water coming out of your hose you manage to get to the bucket at a certain distance. eg 50%, 60% or more of the stream gets to that bucket.

The more tightly focused the beam, the more throw or the greater % of the light emitted gets to where u want it.
- This is achieved by the shape of the reflector or optic AND the size + shape of the light source combined.

The more of the available photons you put or redirect into this beam, the more throw.
- usually achieved by a deeper reflector meaning less light goes into spill.

Now assuming you get these 2 points perfect then you get a perfectly parallel beam (like a laser). Now pump out more light at the source and the light 'appears' to go a longer distance.... but the percentage of the emitted light that makes it to your object, throw, does not change.

/ubbthreads/images/graemlins/dedhorse.gif /ubbthreads/images/graemlins/dedhorse.gif /ubbthreads/images/graemlins/dedhorse.gif

 

[Led_Blind]

Almost forgot to ask.
/ubbthreads/images/graemlins/grin.gif
Don, you got any of those 45mm reflectors in an A-4 (i guess) head you can pass on? I have a smallish farm and use an A-3 to check fences and such at night while riding around on a trail bike. Somethinh like that sould add a bit more throw /ubbthreads/images/graemlins/smile.gif to my current solution /ubbthreads/images/graemlins/grinser2.gif /ubbthreads/images/graemlins/grinser2.gif /ubbthreads/images/graemlins/grinser2.gif

 

[beam_me_up]

what makes a flashlight throw? light of course! Duh! even *I* knew that one

 

[wquiles]

Thanks for the great comparison and the picture of the reflectors /ubbthreads/images/graemlins/grin.gif

Will

 

[asdalton]

[ QUOTE ]
cheesehead said:
Well, duh, an overdriven bulb will throw farther, it has a higher surface brightness (there's your explanation /ubbthreads/images/graemlins/confused.gif). Same like my Maglite with an overdriven 3D bulb in a 4D body will throw farther than an underdriven Thor at 100 watts.

Again, LUMENS DON'T MATTER!!! And neither does Lux. /ubbthreads/images/graemlins/banghead.gif

[/ QUOTE ]

An overdriven bulb causes a flashlight to have better throw because, while everything else is equal, the filament is emitting more total light. In other words, more lumens. And lux (at a given distance) is pretty much the definition of throw.

 

[MaxaBaker]

Cheese Head is right asdalton. The surface brightness of the light source is what does it. Lumens, Lux......they're just along for the ride.

 

[kongfuchicken]

and in order to acheive higher surface brightness, don't we either decrease the point source size or increase the lumen output? (the former by using XSA for instance and the latter by overdriving) Then again, lux readings would have to be measured at an arbitrary distant point chosen to be fair and the surface brightness would be compensated by how well it works with a better/larger reflector.
Frankely, I feel this discussion is on the verge of reaching utter pointlessness...
Depending on your definition of throw, you'll always be able to find an apparently logical way to justify whether lumens ratings matter or not.

 

[The-David]

WOW I think that this poast cooked my brane... /ubbthreads/images/graemlins/touche.gif

 

[MaxaBaker]

[ QUOTE ]
kongfuchicken said:
Frankely, I feel this discussion is on the verge of reaching utter pointlessness...


[/ QUOTE ]

Oh, I thought it was pointless a looong time ago /ubbthreads/images/graemlins/grin.gif


I'll keep my nose out of this thread from now on.

 

[ZeissOEM2]

edit

 

[cheesehead]

OK,

Lumens don't increase throw, a fluorecent light has many more LUMENS than your incandescent, so,... DOES IT THROW FARTHER? NO,...if it does, you win and I'm the moron. OK, enough of ashdalton, etc,...

So, now finally, to make some sense. NO 1, it's surface brightness, so XSA is perfect, HID is next, and incadescents are #3.

Then #2, it's the size of your reflector, (yes, maybe you've heard size doesn't matter,.. hey,... good for you!) But, it does,...and you can get an HID,... or even an incadescent to throw father than a Maxabeam.

 

[turbodog]

[ QUOTE ]
cheesehead said:
[ QUOTE ]
thesurefire said:
So if I'm understanding you correctly you are saying Lux matters, but the "measure of total output of light eminating from the source..." Do? Lux and lumens are related, not very closely, but they still are, thus lumens should matter, correct?

Little test: get a 3 and 4 cell maglight. They all should have reflectors that are very close to identical. Get 2 3 cell bulbs. now put 1 in each mag and turn them on. Witch one will throw further? The stock or the overdriven? The overdriven one will I guarantee it. So if lumens don't mater (and by saying lumens don't mater you are implying Lux doesn't matter) please explain to me why the overdriven bulb throws further then the stock bulb.

[/ QUOTE ]

Well, duh, an overdriven bulb will throw farther, it has a higher surface brightness (there's your explanation /ubbthreads/images/graemlins/confused.gif). Same like my Maglite with an overdriven 3D bulb in a 4D body will throw farther than an underdriven Thor at 100 watts.

Again, LUMENS DON'T MATTER!!! And neither does Lux. /ubbthreads/images/graemlins/banghead.gif

[/ QUOTE ]

Ah, here's some more of that useless/wrong/misdirected information.

 

[turbodog]

[ QUOTE ]
cheesehead said:
OK,

Lumens don't increase throw, a fluorecent light has many more LUMENS than your incandescent, so,... DOES IT THROW FARTHER? NO,...if it does, you win and I'm the moron. OK, enough of ashdalton, etc,...

So, now finally, to make some sense. NO 1, it's surface brightness, so XSA is perfect, HID is next, and incadescents are #3.

Then #2, it's the size of your reflector, (yes, maybe you've heard size doesn't matter,.. hey,... good for you!) But, it does,...and you can get an HID,... or even an incadescent to throw father than a Maxabeam.

[/ QUOTE ]

You're making comparisons between the wrong things. Terminology needs work also.

Surface brightness? You mean color temp? No, can't be that. Hmmmmm, then that only leaves..... lumens!

But unfocused lumens can be wasted. A surefire L4 puts out 60+ lumens, yet only "throws" 50 feet or so. A 2d mag with stock bulb will "throw" 300+ feet.... yet it only pushes 15 or so lumens?

Furthermore, a 6d mag will "out-throw" a 2d one. Why? Same reflector, more photons, more lumens. As light is scattered by dust/etc on the way to the target the higher lumen light simply has more light/photons/etc left over at a given distance.

For meaningful discussion to take place on this topic you HAVE to standardize your terminology.

 

[turbodog]

Surface brightness, as the term implies, has got to mean lumens. What other choices do we have? Color temp... that's stupid.

Why lumens? Candlepower and lux are intensity measurements, usually taken at a distance. Lumens is a far more accurate term. A possible exception is MSP or mean spherical candlepower. The only mfg that uses this is Mag. And, when you get right down to it, MSP and Lumens are really measuring the same thing.

 

[MaxaBaker]

Does anyone know where Ra went?!?!? He is an optical engineer and an expert on all of this stuff. Why did he leave CPF, WHY??!?!?!?!

 

[thesurefire]

[ QUOTE ]
turbodog said:
Surface brightness? You mean color temp? No, can't be that. Hmmmmm, then that only leaves..... lumens!

But unfocused lumens can be wasted. A surefire L4 puts out 60+ lumens, yet only "throws" 50 feet or so. A 2d mag with stock bulb will "throw" 300+ feet.... yet it only pushes 15 or so lumens?

Furthermore, a 6d mag will "out-throw" a 2d one. Why? Same reflector, more photons, more lumens. As light is scattered by dust/etc on the way to the target the higher lumen light simply has more light/photons/etc left over at a given distance.

For meaningful discussion to take place on this topic you HAVE to standardize your terminology.

[/ QUOTE ]

I agree 100% with everything turbodog said, more photons is more lumens, this is that base, then things like reflector size come into play. Look at the sun, it has no problem throwing to earth, given its huge lumen output. and no dont tell me its because the sun is such a small point sorce /ubbthreads/images/graemlins/tongue.gif

So to start us off, can we all agree that throw is defined as "the distance at witch a light is able to perduce useable light"

And then define useable light as "light with an output of 30 lux or greater"

maxabaker I dont know where RA when, but I thought he was an optical engineer, doing lots with optics /ubbthreads/images/graemlins/confused.gif