Green Laser Pointers

[circumpolar]

Hi guys,

When I push my Dob towards a target, I tend to crouch behind the scope and place my chin on the tube, align the target just above my finder scope and then walk around to the finder to fine tune, or am I the only one doing this little dance?
I was wondering if using a green laser pointer mounted on the scope is accurate enough for the initial alignment. Do many use this set-up.

Thoughts.

[ving]

I do similar... tho seated i lean across looking above the finder for rough line up and then thru the finder.
there are some companies who make a laser finder of sorts. bintel sell them :)

[Miaplacidus]

Don't tell anyone, but I find a green laser pointer more useful than my Telrad. I own two, and despite all you read about the potential for spoiling astrophotographer's fun at star parties, my experience is that people actually love them. Put one each on a couple of GOTOs and everyone is able to find pretty much everything.

Cheers,

Brian.

[circumpolar]

I do a lot of entertaining at home so lots of people see (and comment) on my movements. It seems like a cool (and ezy) way to select targets while standing.
I'm assuming that 10mW is beter then 5mW.

[RB]

I love my green laser.
It's so easy to line things up.
I use it now instead of the finder scope and/or Telrad.

:abduct:

[barees63]

How did you mount it? I have looked at the scopestuff.com laser mount and it looks quite nice and seems like the dovetail option might fit the GSO finder mount..

[RB]

Yep, mine came with a "finder scope" type holder with three alignment screws.
The base was slightly different to my Orion 80ED finder scope holder so I went to Bintel and got a base to fit into the scope holder and bolted it onto the bottom part of the laser mount.
So I can slide it into the 80ED finder holder and screw it on just like a finder scope.

[AstroJunk]

http://staff.uow.edu.au/ohs/workingsafely/lasersafety/OHS107-Laser_Safety_Guidelines.pdf

Class 1 lasers are those which are incapable of damaging the eyes or skin because of either engineered design or inherently low power output. The lasers used in CD players are the most common example of this category.

Class 2 lasers have sufficient power output to cause damage to the eyes if viewed continuously. However, their outputs are low enough to allow the natural aversion responses, such as blinking, to prevent damage. Additional hazard control measures take the form of cautionary signs or labels. The laser pointers often used by conference presenters are common examples.

Class 3A lasers have the potential to cause damage to the eyes from intra-beam viewing and precautions are required to prevent both direct viewing or viewing with optical instruments.

Class 3B (restricted) lasers operate at the same power levels as class 3A but have higher irradiance, i.e. higher power density, and consequently have some additional restrictions on use.

Class 3B lasers are more hazardous because of either higher output or operation outside visible wavelengths. In addition, specular reflections may also be hazardous. In general, more stringent controls are needed to prevent exposure.

Class 4 lasers are high power devices capable of producing eye damage even from diffuse reflection. Skin damage is also possible from even brief exposures. Class 4 lasers may also constitute a fire hazard. Examples of class 4 lasers include entertainment lasers, surgical lasers and those used in the plastic, wood and metal fabrication industries.

I'm an astronomer. I treat my class 3a laser with utmost respect; its a great tool, but I value my sight. If you have a 3b device (a modded pen device above 5mW for eg) then you need to be either licenced or locked up.

In the UK, where health and safety is taken seriously, they are illegal above 1mW (class 2) for general use.

I don't like to preach to grown ups, but this is a beginners forum ...

[Argonavis]

Whilst I enjoy my green laser, I wonder about the wisdom of their ready availability. Younger members of the species seem keen to relieve me of it to do who knows what mischief. I refuse. They ask where to get one, I am vague. Despite my awareness and prudent use, I once inadvertently and carelessly pointed one at someone (on their body fortunately) whilst lifting it to the sky. Mine is tuned up to 5mw, and whilst it can dazzle, momentary exposure should not cause permanent damage to the eye. I understand that USQ (or QUT?) has banned the low power red pointers.

Once, at a dark sky site at night, I observed a fellow amateur point a green laser at an approaching car who had their headlights on high beam. Well, they did then go away.

[OneOfOne]

I bought a Lumicon laser bracket from the US, now you can get them from Bintel, and mounted it on the tube next to the finder. To keep it in easy alignment I bored out a piece of PVC to a snug fit (you may not have a lathe though) and then put in a couple of screws to hold it in position. One screw holds it in while the other presses on the switch, that way I can turn the laser on while I align the scope roughly with a star and then turn it off while I finish the alignment. The tube allows me to take the pointer out if I want to point it at something and put it back in without needing to reset everything. I can now align my scope in about 5 minutes and my back doesn't "go" while trying to stand on my head to get the finder centred. Once my scope is set, I rarely need to use it again for the whole night. In your case you may need to use it more often so flashing it around at a dark site may cause some concern to other people, their imagers, and it may even effect peoples night adaption a bit too, which I don't think they would appreciate. Mind you, lighting up a fag in the middle of the night is FAR worse!

If you are in Victoria, of course, you need to liscence it, which mine is. Pretty simple procedure, you just have to fork out more than $100 for three years. Normally mine is mounted in its tube and kept with the scope so no children would have access to it unless they new where it was and how to remove it.

Always watch out for aircraft before using it, last year a guy in the US got in a lot of trouble (but he did a lot of stupid things and tried blame his daughter for pointing it).

In summary though, the best thing since sliced bread!

[rmcpb]

With some common sense and observing ground manners these are great tools for aiming a scope and showing objects to other observers.

[janoskiss]

Trouble is that common sense is not so common, Rob. I was recently at a talk by an expert (with a PhD in biochemistry) who was using one of them 2-5mW green lasers as a pointer. Occasionally, he would forget to take his thumb off the button as wave his arms around at the same time. I was :scared:

[rmcpb]

Forget the PhD as an indication of common sense. I have worked in the higher ed industry for over 30 years and we often laugh that common sense in inversely proportional to intelligence ;) Of course there are enough exceptions to this rule to prove it.

[mickoking]

G,day cobbers,

I'm contemplating purchasing a laser finder. Is 5mW sufficient for moderately light polluted skies? or is it better to go to say 10mW?:help:

[OneOfOne]

Mine is a 5 and is quite sufficient for the "burbs" of Melbourne from about the time the Sun finally goes down...don't really need it to get very dark. Any light pollution you have in WA has got to be nothing compared to Vic or NSW.

[AstroJunk]

And I thought you were proudly low-tech ;)

[mickoking]

D'OH :doh:

I have done a bit of reserch and for what a laser pointer does it's a bit pricey me thinks. I will stick to my very low tech finderscope for the forseeable future :thumbsup: