Seeing was better than average on the night of the 28th and I was able to try two different optical configurations on Saturn.
The first was using a Televue 2.5x Powermate, which given my camera arrangement actually gives me about f/22. With this setup I can get 30fps on L, but RGB only go to 15 fps.
The second was with a Televue 3x barlow, which actually yields more like f/33 for my setup. With this I could still get 30fps for L, but with only about 60% hist at max gain, and RGB were limited to 7.5 fps.
Both sets stacked with AS!2 and sharpened in Registax 6. For the purposes of comparison, the f/22 image has been scaled up by 1.5x in gimp post stacking.
Given my preference for over sharpening detail, I think I like the upscaled f/22 version better.
Thanks everyone for your votes. There is obviously a clear preference for the second image. Even the fact that there is one extra moon visible in the first couldn't swing it!
Not sure why the C-ring is brighter in the second image, and why the Cassini division is clearer around the back of the planet, but certainly the smoothness of the planet clouds is because of less sharpening at the wavelets stage.
Imaging at f/33 with a C11 is a lot more painful -- it's harder to focus, takes longer to get enough frames, and I need to manually adjust the guiding a bit during capture, since the image uses up so much of the frame -- so I think I will have a go at re-processing the f/22 image with a bit more smoothness. If I can get the same result in processing, it will be easier to capture.
Alternatively, I might just need a bigger scope and more sensitive camera!
Very good images Ivan. I also prefer #2. Have you tried using drizzle on the f22 version? - could be enough detail there to get some benefit. Regards Ray
