Edge noise?

betonos

Hi,

I'm new to seestar, but haven't seen this discussed here. When I take images, I see certain amount of noise towards the edge of the image. Is this normal?! See on attached image, it's generally noisy, but I've marked the places in which it's extra noisy.

starnet

betonos This is normal. It depends on how long your exposure is and the relation between the variable Alt/Az position relative to the fixed RA/Dec coordinates of your target, leading to field rotation and all that. It starts as noise on the edge of the image, but with exposures longer then an hour or so it will grow and affect a larger portion of the image. Exposures longer than an hour or so are not very practical. If you need to stack for linger than that you will get better results with multiple one hour exposures done over multiple consecutive nights, taken at more or less the same ti.e. Assuming you have the clear skies and give up sleep conpletely for multiple nights in a row.

Regulus136

Due to the combination of field rotation and your latitude or the declination of the object, what you're experiencing is normal. There may be times when it's better or worse. The only way to avoid this phenomenon is by using an EQ mount, but that's not recommended.

I hope that helps!

Digital Don

I believe that is due to the fact the Seestar processing software uses 'dithering'. I normally don't see Field rotation effects unless the exposure is more than 30 minutes or so.

Don