First attempts at planetary work

[Snoani]

Good evening

While my passion is very much deep sky work, I picked is a Skymax 127 SCT from eBay a few months ago and with the addition of a ASI 224MC and Celestron 2x barlow I decided to give Jupiter and Saturn a try last night.  I was not really expecting to get much on the first run but I am pleasantly surprised at what I have been able to achieve.   

Both of these images are made up of a stack of 1000 frames processed using PIPP, AutoStakkert and Registax6.  The whole process has been quite an eye opener and much different that I am used to.  

Due to the atmospheric turbulence I did struggle to find the best focus that I could and think they were probably a little off, so I did also sharpen them in Photoshop.  Any tips on focusing would be appreciated.  I do have a bahtinov mask for the scope and I wonder if focusing on a star before slewing to the planets would be sufficient or if there are any other tricks.  

Thanks for looking. 

Jem

 

 

Edited August 17, 2021 by Snoani

[symmetal]

Pretty good for first planetary. 🙂

Yes, focusing on a star with a bahtinov mask is a useful way to achieve focus and is what I do. Some use Jupiter's moons to focus with a mask but I haven't tried that.

Your background is heavily black clipped. you need to check the preview histogram on your capture software and increase the camera offset (sometimes labelled brightness) so the full background sky hump on the left is to the right of the left edge of the histogram so none of it is clipped. During wavelet sharpening and other processing you can end up clipping the data if it's close to the left, or right, edges of the histogram. The offset used is normally higher than you would use in DSO imaging.

Use high gain and set exposure to 5mS or so to help freeze the seeing variations. Don't worry about it looking very noisy in preview or underexposed in the histogram. Capture in 8 bit mode and also try high gain mode on the camera to increase the fps, and disable gamma during capture, or set it to 50 which turns it off anyway. Applying gamma takes processor time so lowers fps. Use ser format rather than avi for capture as it's more versatile and better supported. Use as small a region of interest  (ROI) to keep the planet in view during a capture, again to increase fps. Only ROI height affects fps, the width doesn't.

Here's the processing flow I followed when starting out which is useful. Registax wavelets is a bit of a dark art but this video helps. 

Imppg is also good for deconvolution sharpening, particularly on the sun and moon, but it only works on mono images so you'll need to split rgb to three mono channels if you want to use it for colour.

Good luck.😊

Alan

 

Edited August 17, 2021 by symmetal

[Snoani]

Thank you very much for your comprehensive advice.  I am sure that it will be invaluable in my next attempt and it is very much appreciated.  

Jem