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Polar Alignment - new funcionality

Posted: Fri Sep 25, 2026 1:29 pm
by carlomuccini
Hi

I’ve noticed that the post on "Polar Alignment via Platesolving" is attracting a lot of attention and has a large following.
I normally use SharpCap's built-in function because I have a clear view of the North Celestial Pole, so I don't face the issue that those who cannot "see" Polaris do.

I was wondering at this point why not *also* implement Bigourdan's method in SharpCap.
It wouldn't be the first choice for many, but for many others, it would be a lifesaver.
With a little practice, it takes about ten minutes, but the result would be guaranteed.

I’ll briefly summarize it here for anyone who might not be familiar with it.

The Bigourdan method (or drift method) is the most precise polar alignment technique for equatorial mounts; it is ideal for long-exposure astrophotography and can be used even when the North Star is not visible.
Formalized by the French astronomer Guillaume Bigourdan, it relies on observing the "drift" (spurious movement) of a star within an eyepiece reticle, ignoring right ascension movements and correcting one axis at a time.

Perhaps it wouldn't be too difficult to implement it along the lines of the current method, which works wonderfully well.

Carlo

Re: Polar Alignment - new funcionality

Posted: Fri Sep 25, 2026 4:27 pm
by Jean-Francois
Hello Carlo,

Do you use PHD2 ? If yes, then PHD2 has already the drift (Bigourdan) alignment method.
It has some guided steps for the ~ 90° pointing direction and a graphic.
You can do the same with "a little" bit programming in a script in SharpCap ... but why, if it is already useful in PHD2 ?

Jean-Francois