getting scamed on lasers

hey guys, my first post, but about two years ago i bought a 5mw laser at a convention and i thought it was very bright, a few months after that i bought another 5mw laser that me and my dad agreed was twice as bright and blinding for us compared to the other one, does this mean it's really 5mw or is the other 5mw and this one is more powerful? now my really bright one has like a cloud around it when you shine it, i think cause its getting old, so i decided to buy a new one

i recently got a 25mw laser for like 40 bucks on ebay, i havent tested it for real yet but it doesnt have the cloud when you shine it (its a clean dot) so its hard to say if its brighter or not, since my other one like lights up the whole wall, is there anyway to test to see if its really 25mw? thanks

oh btw on ebay he said it was 20MW and the one i got says <25MW

Well, I suppose you have two choices. Find someone with a real calibrated laser power meter, and have them measure it, or read the forum sticky post titled "Power measurement". You may not be able to figure out the exact mw they are putting out, but you can certainly tell their relative brightnesses.

The "cloud" you describe sounds like a bloom effect on a pot modded pointer. You may be able to decrease the pot setting slightly and get a cleaner beam. Search the forums for info on how to do this.

Maybe try cleaning the lense as well.

You never know what you will get off of fleabay. I think there should be a visible difference between a <5 mW and a <25mW. My pot modded leadlight is quite a bit brighter than a true 5mW, and I'm guessing it's around 15-20mW.