EDIT: new Situation, today's dev patch made lasers have much bigger range.
However, they still behave as if using perfect optics in a vacuum. (21.08.2013, 13:30)

SITUATION: Currently, IR Laser pointers for Rifles have a finite distance to which they reach. At that distance, the laser beam cuts off apruptly. This is consistent with the behaviour of IR lasers in OA.

This is okay for general purpose use, where the laser is employed as an aiming aid in CQB. However, for specialty use, the laser becomes useless in this purpose.

EXPECTED BEHAVIOUR: Laser beams are not sticks that remain at a fixed thickness and strength along their beam path. They are not fully opaque, and their visibility in the Air is dependent on the density of intermediate medium. In a vacuum, the IR beam would not be visible in the air at all.

Optics are subject to internal reflection and dispersion, no lens is perfect, furthermore, the atmosphere along the beam path scatters the beam, resulting in blooming. This means, the further the beam gets away from the source, the larger the beam gets in diameter, and the weaker it becomes. The actual intensity of a beam at the target is subject to complex mathematics, however I believe seeing as Lasers are a massively important part of combat in this day and age, it is worth at least integrating an approximation for all laser devices (incl. weapons) in the game.

I have retrieved some formulae from atomic rockets that may be of use.

FEATURE REQUEST in bullet points:

-Beam Dispersion
-Beam Dissipation
-Spot Size bloom
-Weather effects on Laser devices

Not for Arma 3 final, but possibly as a feature for future expansion. At least basic functionality of beam dissipation should at least be implemented to stop the ugly "lasers are sticks" effect we currently have. {F19633} {F19634} {F19635} {F19636}