compass alignment?

[jnb]

I often "polar align" using compass, the altitude scale on my mount and a bit of guesswork. It is adequate for visual work where I will be starhopping but not for photographic work. The problems being that not only is a compass not that accurate or consistent but unless you permanently fix the compass to the mount it won't be that accurately aligned to the mount.

[stargazerlily]

I often "polar align" using compass, the altitude scale on my mount and a bit of guesswork. It is adequate for visual work where I will be starhopping but not for photographic work. The problems being that not only is a compass not that accurate or consistent but unless you permanently fix the compass to the mount it won't be that accurately aligned to the mount.

Yes ... this is adding to my worry ... using a compass.  In my approach all I use a compass for is to get the tripod leg with the N (north) letter roughly aligned to north.  I then align the mount using the polar scope.

In theory, it shouldn't matter which way the tripod legs are pointing as it is the mount that must be aligned to north.  It is obviously easier to polar align when the leg with the N (north) letter is pointing towards north.

Pete

[D4N]

I'm not familiar with the HEQ5 polarscope but my one you don't put Polaris in the middle since Polaris isn't at true North. There are graduated circles that Polaris sits on.

Polaris doesn't move much but it makes a small circle around the North celestial pole, it's altitude is directly related to your latitude.

If your rough North alignment is a long way out you may need to consider magnetic variation, the compass on a phone will often correct for this automatically (iPhones do but can also be set to show magnetic North). Variation can be huge, there are some places where magnetic North is actually closer to South than to true North.

If you have a steel tripod that can also throw off the compass.

TSED70Q, iOptron Smart EQ pro, ASI-120MM, Finepix S5 pro.

[mballak]

Your CGEM has a polar align routine built into it, where you don't need Polaris. I haven't used it so I can't speak to its accuracy for AP but it's there.