It was a long time ago I observed Jupiter with my 12". I didn't see much detail on the planet, except for the NEB. It was the first time I saw detail IN the belt (two bright streaks). Between the two bays (a big and a small one) there was a darker section. I'm not sure about the festoon. The shadow of Europa was just under the GRS (just visible on the edge). It looked like a air-balloon with a basket.
I guess I messed up the south side (up) of the planet. The three belts must be much closer one another and more to the south.
8B pencil and cotton swaps, permanent marker, layout in Paint.
21/08/2010, 2.15-2.45 UT, 12" @ x171, diam. 48", mag. -2.8, alt. 38°, CM1 = 238°, CM2 = 95°.