Polar aligning with the help of a laser pointer

[Swagman105]

Hoping this idea is not crazy and willing for some help and advice as I was unable to find any other threads about it.
My problem is that I have trouble aligning my equatorial mount due light pollution coupled with personal issues like eyesight and flexibility to get down to view through a polarscope.
I invested in a Polemaster and have had some success but it does require that at least you get in the ballpark of that obscure thing the SCP.
Because my setup needs to be moved and polar aligned each time I use it these issues are an ongoing problem for me.
I also have a Sky Prodigy 6 and the thought occurred that maybe I could use this to help me to get close enough to the SCP to be able to finish the job with the Polemaster.
What I want to try is to use the SP6 to automatically align itself (easy as pie) and set it to GOTO -90 degrees DEC. I have done this and it seems to get very close (within an arc minute) of the cordinate.
My intention is to have the red dot finder on the SP6 replaced with a bracket and holder for a laser pointer which hopefully when illuminated would give me an artificial point in the sky to aim the Polemaster/polarscope at.
The issues I need some advice on are
1 Would there be a problem (legally and practically) in using a laser pointer of sufficient power to be suitable for this purpose
2 What would be the best bracket with which to replace the red dot finder on the Prodigy's 6 inch SCT tube. I would still like to do this to allow the use of a small optical finder.
3 What would the best way be to secure such a bracket to the SCT tube.
Any advice will be gratefully received

[glend]

I always discourage any laser use.

There are self-aligning mounts, and add-on systems like Starsense, that will work with what can be seen. That might be the easiest given your eyesight problems.

[Swagman105]

Thanks for that Glen
I too am not overly thrilled at the prospect of using a laser.
I was not aware that the starsense came as a stand alone accessory apart from the sky prodigy.
Having now looked at their pricing $600 - $700, It may be a bit out of my reach and also raises another question as to whether it would work on mounts other than Celestron's own. My EQ mount is an Ioptron.
Geoff

[John K]

Hi Geoff,

Another alternative you may wish to use is to simply to shine a bright LED torch which ideally snuggly/perfectly fits inside your focuser draw tube down your telescope tube and back up into the sky and then align the telescope tube to the SCP whilst looking through binoculars and a set of star charts.

Certainly works for me in a dark sky and from there on I can drift align.

John K.

[Swagman105]

Another good option to try if I can find a good strong led torch narrow enough.
I would still need to replace the Sky Prodigy red dot finder which is screwed directly to the base of the tube with a bracket.
Any one done this?

[jenchris]

You can shine a laser through your ota as well. Works well

[raymo]

Just google the DARV method by Robert Vice. It doesn't matter whether
you can see the pole area, and no need to break your neck trying
to look through the polar scope, and light pollution doesn't matter
either, and your eyesight is irrelevant, unless you are nearly blind.
You just need your scope, mount, and a DSLR.
It will probably take around 45-60 mins the first time you try it, but
you will quickly get it down to around 15mins for alignment good
enough for your needs. Once you have really good alignment, mark
the positions of the tripod legs on the ground, and if you don't disturb
the alt/az and altitude settings, you will already be close next time you set up, and will only need a brief DARV run[ say 5-10mins].
raymo

[xelasnave]

You should be able to drop a mount on the ground and it links to the gps and adjusts via the built in motors.
Alex

[doppler]

If it got too easy then where would the fun (and sense of achievement) be. I for one like the sitting outside under the stars doing the capturing side of things, not the complicated data crunching on a computer.
I suppose eventually someone will come up with an astro program that automates the whole processing side of things to yield perfect results every time?

[xelasnave]

Yes Rick its an excuse to stay outside for me...

I polar aligned on my get away with the scope in home posiyion and taking short captures to show a radius whichvpoints to scp. Just adjust the mount until stars potate in field of view.
I havent checked that scope points exact but it got close.
Scope to mount angle should be checked if pointing the same alignment this way would be lerfect.
But using short captures means you probably can get away with not perfect.
Alex

[redbeard]

Hi Swagman,

Lasers are great and will do well for you with all the things you have mentioned.

I used to use one and it was very easy to use the hand controller for my scope to slew to the star using the laser as a guide. I use this when polar aligning. 10mw Green laser is perfect.

Lasers are very useful for this and they are safe when used with common sense. There are a few people that think lasers are bad but everyone I have met that use lasers are intelligent people that have common sense and there have been 0 negative issues. I guess some people have seen idiots use lasers.





Check with your local state laws. Some require that you are part of an astronomy club but other states may be different.

Practically they are fun and easy to use, I used to simply hold my finger on the laser on button whilst slewing. The laser only needs to be on for a short amount of time.




This works well, see pics, home made but you can see how easy it would be to make of buy something similar.
222329

222330






Double sided auto adhesive tape - works very well so make sure you put it somewhere that does not get in the way of other bits on tube.

Cheers,

Damien.

[SteveInNZ]

You already have the tools you need in your iOptron mount. This assumes you have the location and time set correctly.

Do whatever you need to do to have the two axis swing freely. With the counterweight on and no OTA, the counterweight will hang vertically. Lock the RA. Put on the OTA and rotate it so that is pointing to where the pole would be if it were polar aligned. Lock the Dec.

This is called the home position.
Turn on the mount. Unless you have told it otherwise, the mount assumes that it will start in this position. If you are unsure, use the "Set Home Position" function. It pays to mark this position on the mount so you can just set it there every time.

Without doing any further alignment, tell it to go to something easy to see and unmistakable like the Moon, Jupiter,Saturn, M42, etc. It will go to that place assuming that you were pointing to the pole when you started. So now you move the mount in Alt-Az to get that object in the finderscope and then the main scope. It's a good time to check that the finder is aligned to the scope. Tell the mount to go back to the home position.
You are now roughly polar aligned.

Now do your Polemaster thing and then cycle the power to your mount.

Steve.

[Merlin66]

Here in Victoria a Police Permit/ Licence is required for all laser pointers.
Being a member of the ASV etc doesn’t count.

[baileys2611]

Yes, all states and territories except ACT, NSW and QLD need permits and licenses for laser pointers: http://www.police.nsw.gov.au/online_services/firearms/laser_pointers/laser_pointers_-_questions_and_answers

[Swagman105]

Thanks to everyone who responded to my post. You have provided a small treasury of information to go on with.
I like StevinNZs suggestion about just moving the Ioptron mount around when set in home position to locate an easy to see pre GOTO'd object.
I had already followed Paul Chasse's video on home positioning a ZEQ with a grooved level so it will be interesting to follow Steve's slightly different approach using the freeswinging ability of the mount and see whether it lines up with my own home marks.
No doubt there will be some practical learning to master when I next get the opportunity with a clear enough sky.
I will post again after I have tried it out to share my success or failure.
Geoff

[SteveInNZ]

If you already know the home position using Paul's method, just go with that as long as that's where the mount returns to if you tell it to go home.

Steve.