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Laser Guidance (kind of...)


Mattjohnson1978

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I am just beginning to take some photos of the night sky. Had some reasonable results with M42, but want to try other deep sky objects. The trouble is finding them! M42 is pretty simple to find in a viewfinder but for objects that appear to sit in the middle of nowhere with no visual references around them are proving very tricky.

I see people using laser pens to highlight objects out in the sky and was wondering if anyone has retro fitted one as a kind of viewfinder? I thought if it sat alongside the viewfinder (that is aligned with the scope) and used that to point at the bit of sky I wanted to look at and the job would be done!?

Of course, ideally I will convert my motor drive so I can control it by my laptop but as I'm still paying for Xmas, this might be a cheap and useful mod. Has anyone tried this or got any thoughts?

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Do you mean attaching a laser pointer to your scope so it points in the direction that the scope is pointing?

My side line is making camera control equipment and part of it is a laser beam breaker control system. I can get red laser modules from China for about £3, the green ones are more expensive. The price people seem to charge over here for them is plainly silly!

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Yea that's pretty much it. I can pinpoint by eye where I think I should be looking, so if the scope looks where the laser is I'd have a fighting chance. At the moment, I find myself comparing the stars in the test photo, with the star map to see if I'm pointing in the right direction. Incredibly frustrating and not very successful. And they are so cheap, would be worth spending £10 or so finding out.....

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Yea that's pretty much it. I can pinpoint by eye where I think I should be looking, so if the scope looks where the laser is I'd have a fighting chance. At the moment, I find myself comparing the stars in the test photo, with the star map to see if I'm pointing in the right direction. Incredibly frustrating and not very successful. And they are so cheap, would be worth spending £10 or so finding out.....

Having bought a few different ones there is a vast difference in quality from one to another. The other thing is that they draw a decent amount of power so the ones powered off button cells should be out. I'd look for one powered off a couple of AAA batteries. You need to watch out in relation to your location. You can get into a lot of trouble with lasers in certain areas ie near airports, flight paths etc....

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Yea good point about the flight paths. I should be ok where I am tho. Besides, would only be a few seconds of use while I setup. But what do you think? Does it sound good in principal?

I know about lasers and electronics but my first scope is sat in the living room waiting to be put together :icon_salut: I am very much a beginner with astronomy in practice.

If you get something like this : Green Beam Ray LED Laser Light Pointer Pen Sky Star 1MW | eBay at less than a fiver you will need to:

Firmly attach it to the scope.

Make sure that you can adjust the angle of the pointer

You will need to align your scope on an object and THEN adjust the pointer so that it points at the object. Once you have done that try pointing the scope's laser at something else and try looking through the scope to check it's pointing at the same place as the laser.

This laser is not that powerful BUT do you want to waste £100 on something more powerful before you have tried it out :evil:

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That's spooky. I had already run through in my head about how to attach it and making it adjustable and it was pretty much word for word how you put it! I have access to a small workshop so I think I'm gonna just crack on with it as a mini project. I'm hoping it will make a nice stepping stone to something more sophisticated. Even if it isn't spot on accurate, it has to be better than stabbing in the dark? I'll update on here if it was successful or not.

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There are legal constraints on lasers as they are not eye safe as most red lasers are; 5mW should be the maximum. However, having tried to use a green laser as a finder the problem is that they hate the cold. Kept warm in a pocket and brought out to point fine, but mounted out in the cold and most become useless. Kendrick now do a heater for green lasers but it looks as if it is for very thin ones that do use tiny batteries and you would need a mount for it that did not interfere with the dew heater.

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I think all lasers that we would use for this application are not eye safe. I used to use a 2.7 watt green for laser shows pointing at a crowd but the mirrors were scanning at 60k so the energy is spread. That thing could literally burn through paper. Lasers are safe as long as they are in responsible hands and used correctly. It's the idiots the shine them at the cops and people on the bus that have gave them such a bad reputation.

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Try and pick up a red dot finder and attach it to that somehow. seems to have done the trick for mine. Glad I saw this thread or the module would probably still have been in the draw for a few more years :icon_salut:

Heres it mounted up on what I plan to use as my guide scope

ezl505.jpg

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Be very careful if you're anywhere near an aircraft flight path. Lasers have been known to almost blind pilots - you don't want an airliner crashing down on you!!

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The whole aircraft issue is not a problem. I use mine for a few moments to slew too.

The trouble makers actually target aircraft but a laser used as a finder is a solid beam so even if by some chance to did point at an aircraft it would be a fraction of a second....

And as for blinding pilots... trust me - its not that bad!

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I'm not implying anyone here would do such a thing deliberately - and I agree that this should only be a problem if the beam is pointing low in the sky and an aircraft is coming towards you. I apologise if I caused any offence - it certainly wasn't intended.

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And as for blinding pilots... trust me - its not that bad!

I agree. I mentioned something similar to this earlier in the thread. Idiots give lasers bad press. It's when they are landing that it's a danger to them I think. If you can get a laser in a pilots eye then they are probably flying straight towards the ground anyway :) them windows are high.. Unless the have a glass floor fitted I think we're safe :icon_salut:

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