Lens help required (not about lasers)

[borgqueenx]

i have a lasergame gun collection wich is also a hobby of mine...and the inside of those guns use a high powered IR Led with a beam facing forwards.
its about a led called the vishay TSAL6100. it has a beam of 20 degrees. i want to use a lens or optic or whatever to increase the range of this led, so all guns can enjoy from shooting at better distances.

Since laser projection is also alot about optics lenses ect, i thought i'd ask here.

[Eidetic]

I'd love to see pics of your collection! How many do you have? I see them on Ebay all the time and have not bid on any as they seem to be a bit outside the scope of my collection, but not by far. I've been adding non-laser pointers though, so go figure. I see many, many toy ray guns to. Do you collect those too? There must be many who do!

[borgqueenx]

https://twitter.com/borgqueenx/statu...437248/photo/1

nope i love swimming laser projection lasergaming movies and sometimes gaming.

[-bart-]

Are you looking for a final solution, or are you willing to learn how lenses work ?

Do you have a camera or smartphone that can pickup the IR from the led, when projected on a wall ?
Then first try to fiddle around with some lenses with different focal lenghts at varying distances from the barrel.
Soon you find out what works, and what does not.

An ordinairy magnifying glass will be something usefull to start with.

[borgqueenx]

Depends on cost im also ready to experiment.
Tell me some stuff i should try. I have no idea whats best for a 20 degrees ir beam.

[Eidetic]

Choose a lens diameter that's as large as possible and still fit onto the front of the gun, however and where ever you want to mount it. The bigger the diameter the better, and you want it to catch the full 20 degrees of the beam. Make it a plano-convex lens (one flat side). It will be mounted with the flat side toward the LED. The distance from the LED element to the flat side of the lens (when in place) is going to be the focal length you need for the lens. Mount the lens so you can focus it before setting it in place. Get a lens with an antireflection coating for the IR wavelength range you're using. Do a good job.

[borgqueenx]

I have no idea how i could focus a lens. Isnt it basicly trying different distances from the source of light? Thats called focussing right?
The bigger the diameter of the lens the better? Isnt that maybe focussing the beam more and more? Im not looking to focus the beam until the divergence is as low as possible. Its lazer tag and when shooting we dont need the tightest beam in the world...we need some margin of error when shooting someone. Else it would be too hard to exactly hit the sensor of the receiver on another gun.
So im probaly looking at something not too big? Or is the diameter not about divergence?
Thanks