PHD and alignment - Do I change stars?

[swag72]

So, imagine this scenario.

I have been outside trying to check my PA using PHD for over 5 hours now - I am no where nearer than I was, graph all over the place. Anyway - Enough of my stupidity and whinging.

When I started I was using a star on Orions belt as this was almost bang on the celestial equator at the meridian. 5 hours later, the star has moved SIGNIFICANTLY!! Do I need to change stars once it's moved across the sky and try yet another in order to keep going?

[SteveP]

Sarah

Five hours? You deserve a medal.

More seriously, your original star will almost be due west now so unfortunately you will have to select a new star

I wish I could offer you some advice on PHD but I don't use it

Steve

[swag72]

Thanks Steve!

I have given up after 6 hours.

I have come to the conclusion that I MUST be doing something wrong with checking and trying to improve my PA. From a previous thread I am happy that I am essentially doing the PA correctly. But surely it shouldn't take me 6 hours and still not achieve this?

I have followed the steps previously recommended - I can now find a star on the meridian / celestial equator. So what is happening?

Well, the graph is my problem undoubtedly. There have been a number of times this evening when it has shown no drift, BUT it's either been way above or below the middle line. So, in trying to adjust that, it all goes wrong from there.

Please, are there any simple hints or tricks? Anything spring to mind that may help me? Is this really normal?

Perhaps someone can tell me for starters, if I want to move the graph down, do I want to move the star that I am tracking up or down? I think even that may help.

Thanks one and all.

[SteveP]

Sarah

Sorry to hear of your problems. I've no idea how PHD works so best not to comment on something I have no experience of. However 6 hours is way way too long. Using Pempro and my CCD on my mount it takes me about 20-25 mins to get my mount polar aligned. That's pretty normal once you've done it a few times

Good luck

Steve

[MG1]

Hi Sarah...have you checked the drift alignment guide on Ian king's site?

The reason I ask, and I know you are trying to use PhD... But it does explain very well the rather confusing adjustment techniques which I image are similar to the adjustments needed in PhD. Ie star drifts up adjust alt etc... It took me ages to get my head around, but got there in the end and with good alignment can now get 10min+ unguided exposures on my neq6

Sorry that probably doesn't help at all......but it was my 500th post so celebrations!

Best Michael.

[martin_h]

What you need to do is stop PHD tracking for a second, clear the graph then start it re-tracking, it will then re-center the graph.

And yes if the star you are using moves to far west you must choose a new star to use.

To be honest I would have given up after an hour, because the next time you setup you'll only have to do it all over again, get it close and IMAGE!

Try 10/15 min subs...if they look ok - its ok.

[swag72]

When I was making the adjustments, I had stopped PHD, then restarted it again by double clicking the same star and then the PHD button - The graph continued, moving up or down - Had I reset the graph each time I would just have been adjusting for drift and not trying to move the whole damn red line up and down?

I know I am rather OCD about all of this, but I really like to get things right!

Once I am happy with it, I shall be drilling holes in my terrace so that the mount goes back in exactly the same place each time - Does that mean that adjustment the following time I set up would be minimal?

Thanks all, every little bit I pick up makes me a little more confident for next time. I have learnt to clear the graph today, ready for tonight! Here's to hoping that it works tonight.

[jgs001]

I don't think it would Sara.. I think the only way to minimise the adjustments is to have the mount permanently affixed in place. Otherwise, you still have to polar align. Having the leg points marked just makes it quicker to get the mount level and polaris in the polar scope. It'll probably be close...

[martin_h]

Had I reset the graph each time I would just have been adjusting for drift and not trying to move the whole damn red line up and down?

Err Yes!

[swag72]

Thanks!!! LOL!!