Weird Idea's

[aaronsadler]

Just wondering, what would happen if I were to point one of them cheap red lasers through a scope, would it act like finder or what. :shrug:

Sorry to make a new thread but no-where else to ask.

[[1ponders]]

Unfortunately I don't think so Aaron. For one our eyes are least sensitive to red light. Have you noticed that when you use a red laser more often than not you can hardly see the beam. Our eyes are far more sensitive to green. A green laser is much much easier to see. Two: If you shine the laser into the eyepiece of a scope to show you where the scope is pointing, the scope will act in reverse and spread the beam out.

Do this little experiment. Get a very small torch, say a penlight or better yet an LED, and hold it against your finderscope eyepiece. Aim the finderscope to a wall a few meters distance. You will find the circle of light is much bigger than the finder objective. Now I don't know if this is correct but it seems likely to me, that if your lense is convergent one way (light entering from the stars to a focal point) then it seems that it would be divergent the other way around. ie it would spread out becoming fainter and fainter with distance.

[RAJAH235]

:thumbsup: Paul. :D L.

[netwolf]

Not so weird this is being done its called Satellite Laser Ranging.
See link: http://ilrs.gsfc.nasa.gov/
But I belive the use Green lasers for this. But I am a little concerned about using lasers in this way, remember that there are airplanes up there, we dont want these things to blind a pilot vission.

[iceman]

You can shine your laser into your focuser (without the eyepiece) and it will shine the beam back out into space where your scope is pointing.

But that's with a green laser, not a red one for the reasons Paul pointed out.

Others always attach their laser to their scope with a bracket, to as a finder.

[aaronsadler]

Do you guys now how much a green laser would cost and also the rules about using them. I've seen bintel has got one for $149, is there any cheaper and where. Are you not allowed to use them close to an airport or in a city or what, need facts.
:shrug:

[ving]

bintel have such a device now. i was in there yesterday :)

[aaronsadler]

Where in bintel is the bracket, can't find it in online catologue.

Are there any restrictions or rules in use near airport or city?
:shrug:

[iceman]

Don't point it at a plane :)