Thoughts from Starlight Cascade

The allskypi camera upgrade from 0.6 to 0.8 took about 10 minutes and the new software is *amazeballs*

A new web GUI interface for settings which has more info about the settings, the much better dark frames at temps from 23-30C. Unfortunately, I covered the dome with a dark hoodie jacket and that actually insulated enough and blocked the vents enough that the sensor temp actually rose through the night instead of dropping.

Will have to do it again with a smaller black cover that does not cover vents. even so the resulting dark frame at the actual temperature is doing a much better job at removing hot pixels than before.

I will now look at adding outdoor temp and humidity as well to each image.
Two quick sample shots from this morning.

The first at 05:33:06, before dark frames, 60sec exposure, hot pixels EVERYWHERE

The second, at 05:40:27, after using a dark frame taken at 29C, a much better image.

Orion is just on the bottom, Capella near the centre. Cassiopeia near the upper right.

Can’t tell if that is M31 Andromeda Galaxy or not.. there was a lot of cloud starting to come up from the south.

Regulus and Leo are over to the left side. The Big Dipper/Plough upper left.

Great first light results!

The woman on the presentation, Linda Thomas-Fowler, spent about $650USD on the project, mainly for buying a higher end ASI camera, and a new raspberry pi 4, etc. If you had spare bits lying about it would be more on the order of $100-200Can

software project available here: https://github.com/thomasjacquin/allsky

Will be trying to get more dark frames tonight once the sensor temp goes below what we already have… 23C

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.