iceman
29-10-2007, 08:46 AM
This was also captured on Sunday morning, when Saturn was at around 30° altitude. It's currently 18" in diameter, and apparent magnitude 0.79.
It's my first Saturn image since it has come back into the morning sky, and it's reminded me immediately how difficult an object Saturn is to capture. It's very, very dim at the moment. At the focal length I was working at (over 10.5m), the blue channel, even at 7.5fps (1/8s exposure) didn't have any pixel intensity over 30 (even at 100% gain).
I tried capturing a luminance channel, which was brighter, but the atmospheric dispertion at that altitude really blurred the image. The red channel was the sharpest, but I couldn't even make a normal RGB composite because the blue channel was so poor.
So, here's the red channel.
Next time, until Saturn is brighter and higher, I'll reduce the focal length and at least capture a smaller, but more colourful image :)
It's my first Saturn image since it has come back into the morning sky, and it's reminded me immediately how difficult an object Saturn is to capture. It's very, very dim at the moment. At the focal length I was working at (over 10.5m), the blue channel, even at 7.5fps (1/8s exposure) didn't have any pixel intensity over 30 (even at 100% gain).
I tried capturing a luminance channel, which was brighter, but the atmospheric dispertion at that altitude really blurred the image. The red channel was the sharpest, but I couldn't even make a normal RGB composite because the blue channel was so poor.
So, here's the red channel.
Next time, until Saturn is brighter and higher, I'll reduce the focal length and at least capture a smaller, but more colourful image :)