Last night (early this morning) I was setting up a Nexstar 4 a friend kindly gave me.
1: I set the wedge (see photo) to my latitude (35 degrees south).
2: ensured the bottom mounting plate was level (using bubble level)
3: faced the wedge due south (using compasse)
4: Set the scope to point inline with the fork (see photo)
5: Looked through the dot finder expecting to be near the pole (see photo)
What happened next is confusing:
I expected the scope to be pointing at the pole (roughly).
It was way to high (10 degrees to high).
I had to adjust the wedge a wopping 10 degrees to get the pole star in alignment.
This meant the wedge angle was 45 degrees (instead of 35(my latitude)).
My only input is the compass will be 12 degrees off true South.
10 and 12 are close so maybe there is a clue.there?
At 12 noon the Sun with show you true North I would approach it this way...determine North from Sun at noon set wedge to lat angle and see where that gets you.
I presume you don't have a camera on the scope but if you did doing time exposures will guide adjustment.
Maybe the stars you think show the CSP are not the right ones.
Curious but figure true north first.
Good luck.
Alex
Also, markings on mounts are usually very rough... useful for first approximation only.
Your next step should be drift alignment, and this way you can also calibrate your compass and mount markings for next session(s).
Thanks for helping.
I am aware of the magnetic variation (11 degrees east) & did take this into account.
Anyway, that would affect the azimuth more so ( I guess).
My 10 degree error was in declination.
I am aware (plus or minus a few stars) of the south pole star (Polaris Australis).
I didn't expect to be exactly on it, just close ish...
I will take a step back and try using a laser, level and protractor.
As an aside, I am finding astro photography to be 98% preparation...
When you are at latitude 35 degrees south, the south celestial pole is 35 degrees above the horizon, so the inclined face of the wedge plate needs to be 35 degrees from vertical, or 55 degrees above horizontal (not 35 degrees above horizontal).
And when it is only your pride that is dented... well, those dents can usually be hammered out. Especially when it is your good self admitting it to the world!
