Hi guys.
Here's my Saturn image from yesterday, finally got around to finishing the processing.
Quite happy with this image:
- Cassini Division all the way around
- Crepe Ring clearly visible
- Nice banding on the globe
- A "warmer" colour tone
- And a Moon (Tethys)! Which I found hidden away.. I used NASA's solar system simulator to get the P/D data, and it also has moon positions.. I saw it had a moon close to the planet so I went back to photoshop and stretched the levels in that area, and whallah, out came Tethys. Enceladus should've also been captured but I didn't know at the time and cropped it off during my ppmcentre processing.. nevermind
The image was taken at 5fps because the seeing was very good at 7/10. Transparency was also better than normal, so I could have a lower gain for less grain, but I bumped up the gamma to 50% and used the brightness slider as well to give a value of 200 or so in the brightness meter. It looks a bit overexposed in the raw frames but after stacking and wavelets it comes out perfect.
I found that some of my other avi's of Saturn in the same night, where I had a lower brightness value, had the dreaded onion ring after wavelets processing. So i'm convinced that the onion ring effect is caused by underexposure.
The higher gamma value also helps bring out some better colour, and also the crepe ring. Saturation was at 100%.
For those interested, here is my processing workflow for this image..
I captured for 5 minutes at 5fps, giving me 1500 frames to start with.
I used virtualdub to split the avi into bmp's, and then used ppmcentre to rank the frames and crop them to 400x400. I used windows explorer to simply delete the worst 400 frames straight way.
I dragged the remaining 1100 frames into registax, went through the normal processes, but in the wavelets tab I used the histogram tab to reduce the blue weight to 90% and the green weight to 85%. I also moved the blue slider to the left a bit.
I took it to AstraImage, where I split into separate RGB, did LR deconvolution (5/2), recombined. I then adjusted Hue (down) and Saturation (up), and adjusted the colour balance to give it a little more red and less blue. I finished with a Median 5x5 filter to smooth it out.
I took it to Photoshop where I adjusted the levels to set the reduce the red from the background, and stretched the area over Tethys to bring it out.
That's about it
Anyway, comments welcome. It turned out to be a very productive morning. Seeing is king!
Saturn + Tethys, 11/01/2006
Lovely banding on the globe and Tethys! what a bonus. Must find out how you do curves on just a portion of the image, I think my software can only apply across the whole image.
