I got my five cheap 1mW lasers today, and after extensive testing, I can't answer the question I posed in the other thread. I bought them from here,
http://www.ebay.com.au/itm/151247370...84.m1497.l2649
Basically, what I got was two powerful lasers, two weak lasers and one in between the others. The bright ones seemed as good as what I remember 5mW ones were like. The weak lasers were actually what I'd been expecting, but one was just visible, and the other was near invisible - unless I kept pressing its button, which made it seem like there was a weak pulse into the sky.
As I was testing them, it was 11C outside, and I was resting them on the boot of my car. Then I noticed that they all got much dimmer, and two wouldn't work at all. When I went inside and read the instructions, it said their working range is between 15C and 35C.
So I put them in front of the fire and heated them up, put them in my pockets and went outside. They were much brighter again.
To summarise, three of them are great for pointing out stuff in the sky to people, one is passable, and one requires pulsing. But all would require having a spare in one's pocket to keep it warm while the other is in use on a cool night. And only the two brightest may be okay as a laser finder on a telescope, the others would dim to nothing.
The reason I couldn't answer my question is because all five lasers have different brightnesses, so that when I merged two beams together up in the sky, the brightest always dominated, and I couldn't see that I'd added much brightness-wise with the second beam. Though it was fun seeing three parallel beams heading off into space when I wasn't trying to merge them.
Cheers,
Renato