Petavius Crater - One of the finest craters on the moon, near the south-eastern limb (20221012 01:19cedt)

Located very close to the south-eastern limb of the moon, the most favourable time for viewing this crater is when the moon is only three days old, which by itself is already difficult to capture, being so close to the sun and sunset. Or … the alternative is to view this crater 2-3 days after full moon. The nearly full moon (98.5%) still shining brightly in the night sky, but already showing some fringes at its eastern limb, just about right to show the shadows of this beautiful crater

The outer wall of Petavius is unusually wide in proportion to the diameter, and displays a double rim along the south and west sides. The height of the rim varies by as much as 50% from the lowest point. The convex crater floor has been resurfaced by lave flow, and displays a peculiar rille system named the Rime Petavius. The large central mountains are a prominent formation with multiple peaks, climbing 1.7 kilometers above the floor. A deep fracture runs from the peaks toward the southwest rim of the crater.

Clear skies have been sparse these days, with a full moon blowing away the single night that the clouds opened up above my telescopes. As a quick catch, I re-modelled my daytime ‘solar telescope’ into a nightly planetary/moon telescope (my TS102/1100, ie. switching the daystar quark and camera, easier for gearing up as I didn’t want to break my back hauling out the C11), and zoomed in on the moon, getting as close as possible with a 3x Barlow (giving me 3300mm FL at f32, matched with a ASI178MC)

Two images captured with the ASI178 MC, first with just an UV/IR cut filter. A second one with the IR685 filter to dampen the heavy seeing of the night. Although the IR685 limits me to a monochrome end-result, it clearly gives me a better result, also bearing in mind this is a ‘simple’ achromat-scope, not an APO. Main image shows the IR685 capture.

TechnoSky102/1100, Barlow 3x (3300mm/f32), ASI 178MC, EQ6R-Pro
Petavius - 20221012 01:19cedt 1080p 30ms G200 60s UV/IR
Petavius - 20221012 01:25cedt 1080p 100ms G200 60s IR685
600 frames, 35% stacked
AutoStakkert, PixInsight

The ZWO-wbesite indicates that increasing the gain for lucky imaging helps decrease the noise, but I’m weary of getting a lot of graininess, so I’m limiting my gain to 200 - Any advice?

Switching the 1.25” filters between takes is manually (screw-in in the nozzle of the camera), with freezing fingers, which means I lose the orientation of the camera … which is annoying

Running the ASI178MC on USB3.0 through the ASIAIR Pro still gives me quite a slow frame rate, comparable to USB2.0. Also, I don’t seem to be able to get the 2080p video resolution through the ASIAIR Pro. Anybody knows how to fix this?

Although the IR685 image comes out fine (mainly red-channel data), it isn’t crystal-sharp. I’m not sure if this is down to my focus, the way I do the sharpening in the processing (MultiScaleLinearTransformation in PixInsight), or just down to the limits of imaging this at f32. The critical pixel size would be 6.5, whereas the ASI178MC has 2.4 pixel size, so I’m over-sampling on the red-channel anyway - Any advice?

Any constructive guidance is welcome …

Clear Skies everybody! 🤩✨🔭

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