I'm looking to buy one of dragonlasers spartan 447nm blue handhelds. the 400mw has a round beam and the 1watt hasa rectangular beam. WHich is better? Whats the difference between the beams?
Well, it really depends on what you intend to use the laser for. From what I've heard, the 400 mW is better for pointing at things, but if you want absolute burning power, I would definitely go for the 1 W version of the laser.
Will the 1wattnot have a beam that travels as far? I was thinking that a 1 watt beam would be visible at least a couple miles on a clear night even though it has a rectangular beam.
That's correct. A circular beam is always preferable than a rectangular one, and looks nicer when shooting laser beam to a distance. The person at the other end will notice the difference much more than you would. I'd go for the 1 W for obvious reasons.
In my experience the more powerful you go, the less the brightness increases. For example from 5mw to 100 mw of a green, you might see an incredible increase, and then less as you go along.
Yes, the 400mw will be noticeable dimmer than the 1W. No, it probably doesn't matter.
I still would have gone for the 1W though, just because I like the burning power.
EDIT: You shouldn't be looking at the dot anyway, except from long distances. Admire the beam and color outside at night, admire the power indoors with a piece of plastic and goggles.
Not everyone is in to burning things, and if you want to point it at stuff.. 1W is extremely overkill. 400mw is as well actually, but low powered 445 diodes tend to cost even more than high powered ones.
My preference is for a beam that is 3mm, circular, <.1mrad divergence and is as bright as a 5 watt green in any colour. Oh and the beam is room temperature and is always eye safe.
Unfortunately i still haven't found an hands on information of the 400mw version, I know a few have been shipped to users but not sure they have received them yet. There is a review of the 1W here.
The power is intense but the divergence is high, apparently not very good for pointing at the sky and if you point at a cloud it is like an 8 foot beam at that point, at least one owner claims. Burning, YES! Pointing, no.