The crazy world of polar alignment?

[Viv]

I would properly go for galvanized 1" gas pipe so the tripod feet sit in the pipe, getting it level would be easy and the pipe tops could be slightly lower then the ground level, so the wife don't complain when she mowers the lawn...

Thanks - will look at that.

Anyhow - what do you mean wife mow the lawn, that the blokes job (well it is in this house)

[SteveA]

I agree with Eddy....if you are pointing "roughly" in the direction of Polaris, Polaris should be just about the only star visible in the field of Polaris, cerytainly thats all I see, if you see more then, its bound to be the brightest star you see.

Unless you have an illuminated polar scope then the trick you already described of shinning a light across the exit hole on the DEC axis casing where the polar scope is located helps you see the reticule.

One thing you must do however is...rotate the scope on the DEC axis until hole in the the DEC axis shaft scope is ligned up with the polar scope. If you dont do this you wont see a thing !

This commonly puts the scope in a bizzar position, so it may be that its best to do this without the scope on the mount.

Hope this helps

[pel]

Thanks Glowjet, Thanks Scarlet.

[starnut]

I'm new at all this, but what about this "Precise Polar Alignment" using laptop

[661-pete]

One point: whether you're stable on the grass depends a lot on how firm the soil is beneath the grass. If by putting downwards hand pressure on one of the tripod legs, you can make it sink further into the ground, then your ground is probably too soft. If you can't, it's probably stable enough. I always set up on grass but the ground is quite firm.

Another point, and forgive me for stating the patronising obvious! Carry out the final alignment after putting the 'scope and counterweights on the mount! They can make it 'settle' quite a lot!

Also, depending on the type of mount, you will probably have to rotate around the declination axis until you can see through the hole bored across its axis.

If you can see and recognise Polaris easily enough with the naked eye, you could try squatting on the ground and squinting along and above the RA axis of your mount (i.e. not through the polar scope), and tweak it until you have it roughly aligned with Polaris. Polar scopes do not have a high magnification so you should at least be able to get Polaris (the brightest star in the area) in the FOV when you do look through the scope.

And as for reticule illumination: yes I have that problem too, on my Vixen GP (which has an excellent polar scope BTW). The mount came with a pen-torch adaptor collar which fits around the polar scope and is supposed to cast some light on the reticule, but I find it is too bright. Also the torch tends to fall off. So I tend to ask my wife to hold the torch in just the right position so that I get neither too much nor too little light on the reticule. It's a fiddly business but we've now got it worked out to a fine art (if my wife is otherwise occupied* I can do it myself at a pinch, but it's awkward with only 2 hands...).

Hope this helps.

*i.e. asleep...

[pel]

I had a look at that Starnut, I think this is for a Goto type mount.

[eddy]

Mod complete and tested, works a treat....but will only tell for sure when i try it on Polaris! lol

[Astro Imp]

When I set up on grass I put my tripod on three small tiles I had left over from a refurb of the kitchen. Works well, scope doesn't sink and their not big enough to trip over in the dark.

[pel]

Good tip Alan.

[pel]

Well done Eddy, I'll give it a go too.

[Catweazel]

I had a look at that Starnut, I think this is for a Goto type mount.

Yeah, I got really excited until he started talking about GOTO's

If the clouds hold off tonight, I will have another go. To be honest, I think that LP is as big a limiting factor on my AP, and there's nowt I can do about that, and if I go somewhere else, I have to blumming polar align again

I often wonder why nobody invents things for solving these problems, Astronomy seems to be a real DIY hobby in many ways, and there is a gap there for someone clever to come up with an easy solution to quite a number of things. Not me though

[sanmatt]

Just sent the old girl outside to cool and I noticed the spirit level bubble wasnt bang on, I cant quite work out how to fix this. Anyone got an ideas please?

[Viv]

Just sent the old girl outside to cool and I noticed the spirit level bubble wasnt bang on, I cant quite work out how to fix this. Anyone got an ideas please?

I've been told not to trust the bubble - as it may not be level itself !!

Get a small spirit level & use that instead.

Eddy - quick work !! Nice one !

[Tinker1947]

Seems it doesn't have to be a perfect bubble, but as close as you can has to be better....

[jflowers]

When I set up on grass I put my tripod on three small tiles I had left over from a refurb of the kitchen. Works well, scope doesn't sink and their not big enough to trip over in the dark.

I use old tabbaco tins, legs don't suddenly slip off and bury themselves in the grass

[idbvideo]

I tried the xbox live cam for polar alignment, but could not see polaris. I can with a Microsoft Lifecam cinema though

[Woolleson]

I had the same problem, took an age to align

The non illuminated reticule is a mare, spent 20 mins shining my red light over the end to see the cross hairs. I see two stars though, just went for the brightest.........

Oh and it was set off to the NCP, as on the reticule.

Did my first AP the other night, seemed to be right. No trails over 40 mins or so, just tracked not guided, but bloated stars.

I got some AV pads, these not only help with vibrations but can be pegged in place, best £18 I've spent

J

[JamesF]

There are quite a few steps to getting polar alignment and you can't skip any when it comes to imaging, really.

First is to check that the polar scope is aligned with the RA axis. You can do this during the day. Basically you need to make sure that as the RA axis turns, the cross-hairs in the polar scope stay pointing at the same thing.

Then you need to make sure the reticle with the Polaris image on is in the right place. The easiest way I've found to do that is to set the time and date rings to midnight on 1st November and adjust the reticle so Polaris is right at the bottom. You can so this during the day, too.

Then when you get out at night you need to set the date and time on the rings and adjust the mount. It's trivial if you have a mount with an illuminated reticle, but a pain in the neck if you don't. For my EQ3-2 I made an illuminator using some bits of waste pipe and fittings, an LED and an old phone charger. It makes it so easy to do the alignment that I can't be bothered to make a polar scope camera now. It only takes about 30 seconds. If you have a look in the DIY forum you'll find a number of designs for illuminators for both the EQ3-2 and EQ5.

James

[JamesF]

Should have added, AstroBaby of this parish has a guide to doing all the alignment stuff that's worth reading. In my opinion it's easier to align the reticle with Polaris at the bottom on Nov 1st than doing it her way, but that really just a question of what you find most convenient.

James

[JamesF]

I'm not doing well so far this evening. Should also have said:

It's often easier to align the mount with the scope off (and perhaps the weights as well), but if you do that, check the alignment once the scope is on. Doing the major part of the alignment without load on the mount may well help avoid problems with the alt adjustment bolts, which are a bit iffy on all the SW EQ mounts.

James

[sanmatt]

After an hour of the hubby trying to roughly polar align for me, and me then booting the tripod leg, I thought chuff it and came indoors. After threatening to flog everything

Theres a Peter Gabriel programme on BBC4 anyway.

edit - sod the stars, 'Prog at the BBC' is on. Cracking bit of Jethro Tull just now Some ELP, Yes, Caravan, Genesis, Barcly James Harvest etc etc I'm staying in

[182570]

astronomy shed has a tutorial for just this problem

[JamesF]

There are such things as video recorders, you know

Why were you having so much trouble getting the mount aligned?

James

[Catweazel]

After an hour of the hubby trying to roughly polar align for me, and me then booting the tripod leg, I thought chuff it and came indoors. After threatening to flog everything

I say that all the time to the mrs, "it's all going on eBay on Monday", haven't done it yet though.

Theres a Peter Gabriel programme on BBC4 anyway.

edit - sod the stars, 'Prog at the BBC' is on. Cracking bit of Jethro Tull just now Some ELP, Yes, Caravan, Genesis, Barcly James Harvest etc etc I'm staying in

I was still out stargazing, and can't believe I missed this programme, I am a Prog obsessive! Wonder if it's available on iPlayer

Ok, back to polar alignment. After reading some very complex methods for doing this, I had a brainwave. I went out at twilight, whilst sky was still dark blue, and noticed that polaris appears before any of the stars around it. So, I looked through the polar scope, no problem seeing the reticule, and there was Polaris nice and clear! I used the Polar Finderscope program and matched with Polaris in the reticule; Bingo! subsequent AP was much better, with no star trails.

I realise that this is only really useful for back garden astronomy, if you arrive at a dark sky site after dark it won't be much use.

[Redpaul]

reading some very complex methods for doing this, I had a brainwave. I went out at twilight, whilst sky was still dark blue, and noticed that polaris appears before any of the stars around it. So, I looked through the polar scope, no problem seeing the reticule, and there was Polaris nice and clear! I used the Polar Finderscope program and matched with Polaris in the reticule; Bingo! .

As described in post #3

Paul