Help with polar alignment in light-polluted area

[MishMich]

I decided I need to start stretching my subs to more than 30 seconds, and doing a rough by-eye alignment was a bit hit-and-miss. So tonight I attempted my first 'real' polar alignment. The problem is there is a big 3-storey Victorian house to the North, and the sky is just a dim blur to the North, and the three or four stars that are visible are very dim. So, I used the bins to make sure I could see Polaris, then mounted the 80ED and did a rough alignment using that. Then I moved onto the polar scope - which was little better than what I could see visually (I did my best to focus, but the star(s) I could see were so dim I couldn't really tell whether they were in focus or not). Certainly none of the 'markers' or 'cross-hairs' that are supposed to be marked on the polar scope were visible - either on the scope or in the sky through the scope. I decided just to center on the brightest star from the alignment with the ED80 in the polar scope's FOV. However, when I tested this out by doing some 30 second subs on Pleiades, the result was actually worse than my 'rough-and-ready' alignment. I looked through the polar scope again - but the view was so poor by then (with the moon up) that I decided to call it a night. So, I'm a bit stumped how to get past this.

I bought a Synscan upgrade for the HEQ5 from FLO before Xmas, but I am wondering whether it is worth bothering to do it now. The upgrade comes with a LED illuminator for the polar scope - but if I cannot actually get to 'see' what I am trying to align to, the whole upgrade is pretty academic. I'm left wondering whether replacing the polar scope would be of any benefit - if the sky is so poor in that direction? Or is there any other way of doing a polar alignment -such as a laser pointer in place of the polar scope?

How do other people in light-polluted areas manage to get an alignment when you can't make out the stars that tell you the star you are aligned to is Polaris? I seem to get better results using the Celestron Nextar mount with the ED80 than the HEQ5 - but want to use my larger aperture Newtonian as well. Would I be better off getting rid of the HEQ5 and the OTAs I have for it, and getting something like a Celestron or Meade SCT with the Alt-Az GoTo for alignemnt? Would I still have the same issue if I wanted to use them with an equatorial wedge? Have I hit a brick wall in my short-lived journey for now?

M.

[MishMich]

I went through the setup again - from scratch, including checking the polar scope was aligned to the mount (it was), and setting circles, and level, and pointing north, then checked the alt was right using the refractor to align to Polaris first (it wasn't). Then looked through the polaar scope, and used the adjustment bolts to nudge the only star I could make out through it towards the middle, in roughly the point where it ought to be. Not perfect, but at least my 3 minute subs are now as good as my 30 second subs were before.

Question still stands - how can I do better than this?

M.

[Merlin66]

A couple of suggestions...

I'm in the SW London area just inside the M25, so conditions are not the best.

I have an HEQ5pro mounting similar to yours, and need to move it arround the garden to find the best observing position due to other buildings and trees etc.

I can roughly align to a dim Polaris but rely on "drift alignment" to get accuracy. Once I have the mounting properly aligned, I then place markers on the ground to show the position of the legs; then the next time I set up on that point I just re-position the tripod to the marks with no further adjustments.

This works for me.

Ken

[MishMich]

Yes, thanks, I have put some bricks down for now.

M.