Would 4 Fenix L2P's beat 1 Surefire L5?

Need some help here... I was inspired another thread about the inportance of having a backup light. I have been caught without one in a situation that almost involved soiled underwear. Yet, I often forget my second light at home, or don't bring it because I am lazy.

I was going to buy a Surefire L5 this month. However after reading some member comments,I thought about buying 3 or 4 cheaper lights and tapeing-welding-whatever them together to form one bright light when their beams are combined, but still having separate bulbs, batteries and circutry.

I first thought about 3 inova X5's but then switched to Fenix L2P's because of their narrower profile and tail clickie instead of twist operation. My thought being I could have over a day's illumination if I put lithium AA's in each and ran them separately, or a pretty bright light when combined.

My question is this... Based on the numbers I have seen, It seems to me that 4 L2P beams combined would be brighter than 1 L5's beam... Am I right in this or is their some piece of obvious math that I have overlooked? Has anyone else done something like this before? Did it work or not?

Any input would be appreciated...Thanks in advance....

4 L2Ps together would create a slightly wider hotspot and maybe a slightly wider flood compared to 1 L2p. The L5 would still outthrow it considerably. Furthermore, you might get some strange beam patterns happing with the L2p combos.

Just remember, sticking more torches together wont increase your throw and will only moderately increase your flood capabilities.

The L5 is a good, solid light with a nice balance between spot and flood. Not to mention the fact that its got one of the most ergonomic bodies of all the surefires. Sticking 4 L2ps togther probably wont be too ergonomic, not to mention the fact that you have to turn each light on individually....

But by all means try it out - I dont want to discourage you from modding and experimenting. Thats the best way to learn more and its pretty rewarding.

Good luck which ever way you decide to go !

The following words is not an attack, just trying to help Woodrow, thanks!


If you had 4 L2Ps together in a small bundle, i'd imagine the hotspots of each would overlap each other. This will cause the lux of the beam/s to go up, meaning more throw.
So the L2P gets about 800 lux...but of course the brightest part of the hotspot probably won't overlap, but rather, the dimmer circumference of the hotspot...let's give it say 600 lux here. So if all four were on, it'd be 4x600 so your collective hotspot would then be 2400lux, which would actually out-throw the L5 (according to FLR, L5 is 1370 lux). Of course, this would only work if our assumption of 600lux at the weaker area of the hotspot is correct. If the weaker area of the hotspot is above 350 lux, then having all four lights on will outthrow the L5.

FLR gives the output of an L5 as 60. and an L2P as 19. So four L2P's will give 76 output, 16 more than the L5.

Hope this helps.

Hello Woodrow

At first, this is a very nice idea:goodjob:.
I think, Delvance has the right thought of that.But let me ad this.
The throw output of a L5 is 37.01 and of the L2P 28.80. If you build the 4 L2P so together, that the hotspot is concentrated, you don't have a throw of 4 times 28.80 but definetly more than 37.01. And the overall output will likewise be more.
I like my Fenix an imo they have an ideal reflector refer to hotspot and sidespill. They are also very well build.
In your case i'm shure, your idea will work. And you will have a much longer runtime with the security, to have 3 Lights more if one has a fault:thumbsup:.

Another good point is the lifetime of the LED's. The LUX I lives about 99% longer than the LUX V. And you will have the possibility of the 4-stages.

If will come (i hope not) an emergency situation, you can seperate the lights and you have 4 of them for family or friends.

Sorry for the lot of writing, but you can feel, I like your idea a lot.

Best regards

____
Tom

LongJohn,

Certainly sounds good. Throw decreases over distance to the inverse square law i think.

Protaeus said:

Furthermore, you might get some strange beam patterns happing with the L2p combos.

Click to expand...

Several identical lights in parallel (close together) will produce virtually the same beam pattern as just one of the lights would, just brighter. Only very close to the lights would you notice that the beam is produced by multiple L2Ps, I'd say from 0.3-0.5 meters up, the beam would be perfect with L2Ps.

Protaeus said:

Just remember, sticking more torches together wont increase your throw and will only moderately increase your flood capabilities.

Click to expand...

Yes it will! Why? Because our perception of "throw" depends on the amount of photons hitting a target, having 2 identical lights pointing at the same object will double the light and therefore the "throw" (compared to just one light, not the actual distance). Even a 25 cent keychain light has indefinite throw (in a vacuum), so why don't we perceive it as a "thrower"? Because very few photons hit a given target in the distance (but some do!).

Sticking multiple lights together will make all of the beam brighter, the sidespill part as well as the hotspot. This is why there are so many lights using multiple LEDs, which is nothing but sticking several lights together. Why do offroad and rally cars have a row of identical lights on the roof? Why have 2 headlights in your car, when they overlap so much anyway?

Throw is *not* having a narrow beam, it's sending a certain amount of light to a given target in the distance. In other words, a flood light putting out 1000 lumens can have the same throw as a very focused light putting out 50 lumens, which is why increasing the light output (for example by adding more light sources) gives more throw even so you don't change the beam pattern.

Thanks for the advice...I will give it a try and let you know how it works. Its nice to know there are still people out there who can do math...I would be on the short bus team at the math contest.

I'd always go for 4 lights vs 1 since if the L5 fails, you're in the dark. If one L2P fails, you still got 3 more lights working.