Saturn, 2022-08-16 06:38.5 UT. Imaged from my back patio in San Diego. It was couple of days after Saturn's opposition.
I think it came out pretty well. But honestly, I was holding out for a little better. The weather and weather forecasts played me like a fiddle.
My telescope's declination motor encoder had been broken, keeping from imaging Saturn on its opposition day proper. But I replaced the encoder, right around the night of opposition! (Details in an upcoming thread of its own.) After that it was just a matter of waiting for a night of good seeing around midnight*, as Saturn crossed the meridian.
*(That's 1 o'clock midnight now; not 12 o'clock. Midnight
used to occur at 12 AM. But in the US, since the adoption of Daylight Saving Time [and now all year long], midnight and noon now occur at 1 AM and 1 PM respectively, on average within your local time zone. As an amateur astronomer, I'm a little peeved that 12 AM no longer represents roughly the middle of the night anymore, and 12 PM no longer represents the middle of day. By getting rid of the switching between daylight saving and standard time we had a chance to fix this. But we chose the wrong one!)
Anyway, back to Saturn. Saturn was less than a day after opposition, and I had just fixed my telescope. The forecast was amazing. "Excellent" seeing, zero cloud cover, and perfect transparency, every night at midnight for days! This was confirmed by three separate sources that displayed atmospheric "seeing" in their forecasts.
But every night it was the same story: The night started out totally clear with average to above average seeing. But then at about 11 PM (about 2 hours before midnight), the clouds rolled in and the sky turned to complete overcast. Then, almost after-the-fact, the forecasts would update showing clouds for the night, but only for that night.
This repeated every night for days on end. I felt like Charlie Brown trying to kick the football as Lucy Van Pelt pulls it out from under me at the last moment. And I fell for the trick every time.
So this image is what I ended up with. It was captured over an hour before Saturn crossed the meridian for that night. Seeing was OK, maybe above average, but not "excellent." In short, it's not perfect, but it's the best I could get.
Equipment:
Meade 10" LX200-ACF fork-mounted atop an equatorial wedge
Explore Scientific 3x Focal Extender
ZWO Atmospheric Dispersion Corrector (ADC)
Astronomik RGB filter set
ZWO ASI290MM camera
Software:
FireCapture (for acquisition)
AutoStakkert! (for lucky-imaging processing)
RegiStax (for initial wavelet sharpening)
PixInsight (for RGB alignment, constrast & saturation adjustments)
(I considered using WinJUPOS for de-rotation, but decided against it in the end.)
Integration:
Exposure time for individual frames was set to between 10-12 milliseconds. Nine, 3-minute, uncompressed videos were taken, three videos for each color filter, alternating between RGB filters. That's 27 minutes total.
In the lucky imaging stacking, 70% of frames were kept.
In other words, the final image is a composite of around 100,000 individual images, each stretched and warped a little in an attempt to undue the deleterious effects of atmospheric seeing.
I really appreciate the feedback, very useful info for me!
