One thing to be careful of is the type of green laser diode that's in that thing.
If it's the green 532nm DPSS type it's susceptible to the cold nighttime conditions and will fail in the cold.
The better one's (read more expensive types) use the 520nm Direct Diode.
You should also be made aware that the cheap 532nm lasers (usually Chinese made units) often omit the essential IR filter, to cut costs, which cuts out
the dangerous IR from the 808nm IR pump diode used in the DPSS process to create the 532nm green.
This could potentially leak harmful IR that is invisible to the human eye and could be upwards of 10x the stated power of the laser itself.
The reality is that they usually are upwards of 10mW of visible green light.
So potentially you may have upwards of 100mW of IR leaking out.
They usually state that they are 1mW just to get around eBay/Australian restrictions.
If they really were 1mW they'd be useless for Astro work.
The better 520nm Direct diodes dont use the harmful 808nm IR diode pumps so they don't need IR filters and hense are *less* dangerous at levels of 5mW.
You're deceiving yourself if you think these lasers are really only 1mW.
True 1mW lasers cost a lot more.
Watch this:
https://www.youtube.com/watch?v=s1FmxKNysag
Your eyesight can't be repaired once the damage is done.
I'll stick to my Telrad.
Just saying...
RB
