Imaging on multiple nights

[Astro Waves]

Currently sat outside shooting to try get a second night on the Whale Galaxy (on Pleides at moment due to high cloud). Is it recomened to keep the same settings for each time you shoot an object so you can stack everything together or is better to stack the various nights and then blend them? Also if you just process everything together whats the best thing to do about the calibration frames? 

 

CCCHHHEEERRSSS

[tomato]

If you are imaging at around the same temperature each night you can use your dark calibration frames for every session, but if you set up and take down your rig each night you will need to take flat and flat dark frames each time and apply these to the respective light frames taken on each night. Cooled cameras help by not only reducing thermal noise but also ensuring all frames are taken at the same temperature.
 

Once the frames are calibrated you can stack them all together in one go, but as the FOV won’t be exactly the same you will have edge artefacts on the stacked image which will need to be cropped to remove them before processing further.

Do get hold of a copy of “Making every Photon Count” by Steve Richards, it will save you lots of frustration and potentially some money on kit that you might otherwise buy in error.