This image of Saturn was captured on the morning of the 19th January 2009, in variable but at times quite stable seeing conditions. It’s been so long since I’ve seen excellent seeing conditions that I feel i’m over-estimating the conditions of late, and have done so again with this image but it’s the best seeing I’ve had this year so it’s a start at least.
The improved atmospheric stability has helped to make this image my best Saturn for this apparition so far, and it’s giving me inspiration to continue to sacrifice sleep on clear nights and continue imaging. Now I just need a night of excellent seeing to recalibrate my scale and put things back in perspective 🙂
Continue reading for capture and processing information.
I had planned to start capturing from around 2:30am, and had a power-point timer setup to run my mirror cooling system between 1am and 2am, but unfortunately I neglected to set the day of the week on the timer so the cooling system didn’t run at all. It meant there was a 2° difference between the mirror and ambient when I first started, so I had to run the cooling for 30 minutes which brought the temps to within 0.5° of each other – close enough to start capturing.
The image was taken at approx 3:37am local time with my 12″ Newtonian on an EQ6 mount, using my DMK21AU04 imaging camera with a 5x powermate to give a focal length of approx 10 metres. It’s the second of 4 runs that were recorded on that morning, and the red channels were blinked for storm activity, but none was found.
I experimented capturing Luminance data using the clear filter from my Astronomik LRGB Type II filterset, but the data was ultimately not used, as it was not sharp enough after processing. So the image is made up of RGB data captured at 15fps, with gain at max (1023) and Gamma at default (100). I recorded each colour channel for approximately 2 minutes, or until I had about 1800-2000 frames per channel.
The beta version of Registax 5 was used to stack around 900 frames in each channel. The monochrome data was “despeckled” in Photoshop before being taken into Astra Image 2.5Max where LR deconvolution was performed, and merged into an RGB colour image.
Back in Photoshop, levels and saturation layers were used to clean up the final image for presentation.
Thanks for reading.