SharpCap Forums

Does Sharpcap do well with polar alignment on a long focal length scope like 2500mm?
It seems like plate solving is an issue with other software at this focal length.

I have a 10" Meade SCT and using the ASI294MC Pro camera so my field of view is only 0.43° x 0.29°

Thanks in advance.

Hi,

sadly your field of view is too small for the polar alignment to work reliably (or even at all). The FOV needs to be 0.5 degrees in each direction minimum.

A 0.5x reducer might give you enough FOV, although there could be issues if it introduces significant distortion to the view, and anyway it might struggle to illuminate the whole sensor area. I don't think a 0.66x reducer would be enough reduction.

To be honest, the most reliable way to get it working would be to add a 200mm focal length guide scope to your setup with a guide camera. It's also a cheaper option than trying to upgrade to a camera with a big enough sensor to give 0.5x0.5 degrees at 2500mm (tempting though a bigger camera might be!)

cheers,

Robin

Since I use an OAG and don't want to add anything else on the main scope, is something like the iOptron iPolar or QHY Polemaster my next best option?

Hi,

both of those should work (and, as a bonus, both can be used with the SharpCap alignment routine, which I'm told is easier to use than the iPolar/polemaster ones).

cheers,

Robin