Using a laser to Polar Align

[John K]

Hi guys,

In terms of using a laser to get rough polar alignment with a fork mounted telescope, for those who have tried it:

1. How close can you get to the pole (when using binoculars to check pinting location) and when the laser acts like a finderscope and is aligned to your scope?

2. Can you get away with a 1 MW laser in a dark sky?

Clear skies,

John K.

[RB (Andrew)]

If the laser is actually only 1mW, you won't see much.
Most so-called "1mW" lasers are higher power though.
Green is the best for visability.

[Merlin66 (Ken)]

1mW is the legal limit for hand held lasers in Victoria.

John,
I haven't tried it but would be interested in your results.

[RB (Andrew)]

Yes legal limit is 1mW but I bet you'd be hard pressed to actually find a true 1mW (using a proper Laser Power Meter), especially the cheap laser pointers coming out of China.
Green's your best bet for visibility (forget red or violet/blue).

[gary]

Originally Posted by John K

2. Can you get away with a 1 MW laser in a dark sky?

Hi John,

We all really know that you meant 1 mW (1 milliwatt) as opposed to
1 MW (1 Megawatt).

But for your amusement this is what a 1MW laser would give you :-
http://en.wikipedia.org/wiki/Boeing_YAL-1

Handy if you should want to shoot down an incoming tactical ballistic missile.

Best Regards

Gary Kopff
Mt Kuring-Gai NSW

[sharkbite]

Originally Posted by John K

Hi guys,

2. Can you get away with a 1 MW laser in a dark sky?

John K.

just being a s/a here....

if you point a one megawatt laser anywhere you had better
be the military or you are in trouble bigtime....

(i think you mean "mW")

[John K]

Originally Posted by sharkbite

just being a s/a here....

(i think you mean "mW")

Correct.

Just for reference, at the moment I shine an LED torch down my 12.5" f/5 focuser into the sky and I get a beam that allows me to achieve 5 mins exposures. But the beam is round and can be hard to see the absolute contrast with it.