Corrected entry: In a number of battle scenes we see red "laser" lines through the air, obviously from some firearm sighting gear. These would never be visible as lines unless the there was considerable dust in the air, you would only get a spot where the laser hit a surface.
Grumpy Scot
20th Jun 2005
Correction: Yes, but bullets are ripping through plaster, and cotton and sheetrock, etc., filling the air with fine dust that makes the lasers visible.
Grumpy Scot