I have a 100mW DX module. How come I can only focus it so that the beam is thin in one spot, and not the whole distance, like a regular handheld laser? The dot is always like an inch or more in diameter.
Focus the dot of the laser to a really far away object and the beam will stay thin. Another thing you can do (I do this) is to point the laser outside at night and focus it, I am able to get the beam to stay tight for as far as I can see it.