Friday, August 14, 2009
** No telescope used **
This is a composite of 10 shots taken of Jupiter (Io, Europa, Ganymede, and Callisto), with my 500mm f/8 mirror lens and Canon 40D at ISO1600, f/8 (fixed), 1/6 second, showing the major four moons of Jupiter. There are at least 63 moons in all.
To avoid any vibrations in the camera, I used a tripod (w/ ballhead), cable shutter release, and mirror lock-up.
I manually focused in live view at 10X, which was tough because every touch of the lens would wobble the subject all over the place. This is such a tight zoom at 500mm that you can actually see Jupiter moving across the LCD screen. I'd then turn off live view mode, wait a few seconds to let the vibrations stop, then fire the shutter with the cable release. This just flips the mirror up, which causes a tiny amount of vibrations. I waited another couple of seconds, then fired off another cable release shutter click to take the photo.
After ten shots, I cropped the photos as close to the same spot in each photo, then stacked them all together in Lynkeos.
This is screenshot from Stellarium, showing the expected positions of the four moons at the time I took this shot.