This was the last images of the Jupiter imaging test from Friday night, after 2000 EDT and into the next day UTC.
So.. the details… The ZWO ASI290MC camera has been giving unsatisfactory images of late so I borrowed an ASI120MM to try out and try to narrow down what may be happening. So with 0 barlows on the native 1800mm focal length VC200L OTA on a Skywatcher AZ-EQ6GT mount, I started with 15 minutes of trying to find Jupiter… before taking the lens cap off.
Note to self.. take off the lens cap.
OK.. found Jupiter, exposed using firecapture so the histograms come up at 80-85% with default gain and gamma. This turned out to be a 4ms exposure. I normally take a 30 sec firecapture unaligned followed by a 30 second firecapture aligned run to have a baseline for comparison of the seeing that evening.
Last night was average seeing and average transparency… until the clouds came along.
After that a 180sec exposure (old rule of thumb that I used on an older telescope.. the max exposure before Jupiters rotation moved a feature from one pixel to the next.. you don’t want that), I then repeated it all with a x1.5 barlow (there was some dust on it!) at 10ms and then with a x2 barlow (dust on it as well) for a 20ms exposure.

During the very last run (the image above), terrestrial clouds were moving across the face of Jupiter, causing it to totally disappear at times from the display.
I kept a small Region of Interest of about 700×700 pixels, to increase the framerate because of the smaller USB bandwidth needed.
The files were moved from the imaging laptop to the desktop inside the house and today I processed them.
Again, first step is to use PIPP to crop and center at 600×600 pixels and also convert from .SER to .AVI format video.
Then Autostakkert! v3 to analyze and stack using the best 5, 10 and 25% of the frames
I had 11 imaging runs in total and processed all of the best 25% of those. Then I did it again using the best 5%.
The image above shows on the left, the best 5% version and on the right the best 25%.
Possibly because of the clouds, the best 5% is visibly better than the best 25%. There were approx 7500 frames used from the 180sec run, so the best 5% had approx 375 frames and the best 25% had about 1900 frames.
Focus was still difficult but all in all I was satisfied with them. Jupiter was still low in the much, over the Kingston SkyDome (a light pollution dome over the nearest city). Azimuth 147 degrees and altitude 24 degrees.
Jupiter would be at its highest altitude around 22:06, past by bedtime 🙁 That is the end goal however.. picking a night where I can stay up that late.


This is the original best 5% along with the filename which contains many of the processing details.


This is the original best 25%.

I think I will need to use both cameras during the same run to compare them… seeing varies so much from night to night or even from start to end of night that looking at them from different nights yields no new insights.