Laser finders. How do they work ??

[spaceboy]

Hi All

I have been considering getting a laser finder scope and wondered exactly how they work. From what I can make out you have to use a laser pointer but these only work while the power button is depressed. So how do you align the mount while holding the power button at the same time trying not to miss align the pointer in the guider bracket ? Or am I missing some thing ??

[Azure]

Hey Spaceboy,

I've got an Astromaster 130EQ which comes with a laser finder. Essentially there is a scope with two layers of clear plastic instead of just one.

When the power is turned on, by a small switch on the scope, a light lights up a small red dot on each layer in the scope. You move your head around till the two dots are aligned with each other (to find the scope's center) and then you align them with what you're aiming to see.

However it's not terribly easy, I often take at least 3-4 attempts to line up with say, Jupiter. Also, the laser sight might need calibration before use.

Additionally, the two red dots layered means that they make everything in the scope dimmer, so it isn't easy to align with objects that arn't so bright, as they' disappear' when looking through the finder scope.

But you do not have to hold the button down (at least on my scope), as it is a flick switch.

The only other thing I can say is to remember to turn it off, I left mine on for a weekend and it ran out. Mines powered by a 3V cell battery, and it only cost a quid (the battery).

Oh and a lot of people I've talked to have advised to buy a finder scope that doesn't use a laser, it seems to have a very bad reputation. However I'm going to stick with it for the moment, to avoid forking out more cash!

AZ

[spaceboy]

Sorry! I should have been more specific to avoid any confusion. You are correctly referring to a laser finder but these are red dot finders as apposed to a laser finder/ pointers. Astro Engineering Green Laser Pointer and AC666 universal telescope mounting

[freelander86]

have a look here:

Richards Astronomy Blog: Celestron Laser Finder Review

Im not sure which your after but my Astromaster has a been a revalation since I installed a laser finder... I go straight to objects now!

[spaceboy]

Thanks for the info freelander.

[bcfcciderhead]

I have one as a finder and your right, the power only comes on when you hold in the power button.

So what i do is use one of the plastic screws that hold the laser inplace (and for alignment) to screw down until it pushes the power button and turns the laser on, once you have found your target unscrew it until the laser goes off, but you will suffer with the cold, these lasers wont work in the cold, so all i do is put a re-usable hand warmer gel pack around the laser.

[freelander86]

That's a brilliant idea! Using the reusable hand warmers (that I didn't think much of) is a great way to keep the laser warm on a cold night

[m.tweedy]

but you will suffer with the cold, these lasers wont work in the cold, so all i do is put a re-usable hand warmer gel pack around the laser.

I had a similar problem that was solved by wrapping one of my eyepiece dew bands around the front half of the laser

[spaceboy]

Thanks Dave. After a bit of searching I found these High Power Green Laser pointers - MEGAGREEN which I think I will go with. They are out of stock at the mo so I will try your method until then

FYI From what I have read, the way around the cold problem is to use lithium batteries apposed to alkaline.

[glowjet]

I found a small piece of plastic tube that just slips over the button to hold it on

[bcfcciderhead]

FYI From what I have read, the way around the cold problem is to use lithium batteries apposed to alkaline.

Tried that still dont work for long, but it was -2.

After 15mins by the radiator was working fine again

[Gregger]

I love laser pointers but they really dont work in the cold

I have seen this but not used one

Kendrick Laser finder and Pointer Heater  :: Kendrick Dew Control System :: Altair Astro

[spaceboy]

I have read you can keep them in your pocket and then just fire them through your optical finder when needed. Not sure how accurate or even if that is possible but I would be interested in anyone's comments.

Would save on having to purchase a bracket to put the laser on the scope.

[haitch]

my Astromaster has a been a revalation since I installed a laser finder!

Could it also turn a Meade into a Questar?

I have read you can keep them in your pocket and then just fire them through your optical finder when needed. Not sure how accurate or even if that is possible but I would be interested in anyone's comments.

Would save on having to purchase a bracket to put the laser on the scope.

I burnt the crosshair out of a finder with a green laser pointer

[matthewota]

I find that using a Telrad is much cheaper and more effective than using a green laser pointer as a finder. In addition the green laser pointer has a drawback if you live in an urban area where there are a lot of aircraft and helicopters. You would not want to inadvertently illuminate one and blind the pilots.

[Pug]

I think there may be laws against using laser finders, especially near flight paths. Might be worth checking out.

[spaceboy]

I burnt the crosshair out of a finder with a green laser pointer

Thanks for the heads up. I won't be trying that one any time soon.

I find that using a Telrad is much cheaper and more effective than using a green laser pointer as a finder..

Don't stop you getting a pain in your neck though.

I think there may be laws against using laser finders, especially near flight paths. Might be worth checking out.

Can't be a very good law as they sell laser finders for astronomy both for on scopes and pointing out constellations. (As seen on this years "Stargazing live")

[lshu]

My green laser finder has done wonders for me in getting more observing in, mostly because I often don't need to star hop anymore. I just look at an atlas for an object, then point the scope in the sky as close as possible to it with a low-power eyepiece, and viola, there it is.

Find a laser with a constant on-off button switch in the back so you can move your scope hands-free (sorry I live in the US so don't have any suggestions). To have your laser be at least a little cold-proof, find one with an automatic control power (APC) circuit and use lithium batteries.

[lshu]

I can also tell you that shooting the laser through your opical finder or taping it to the side won't work, because it won't accurately point where the scope is looking. I have tried... even if you tape the laser completely straight, the beam coming out of the laser actually comes out a little crooked (I have heard > 8 deg off of straight in one case), so you would need to twist, wiggle, and space the laser until it points generally in the right direction. It's much easier to have an adjustable bracket.

[spaceboy]

Thanks Ishu