I had my Zeiss Telemator and my 6" f/8 newtonian out looking at shadow transits on Jupiter. Io and Europa were passing in front of the disk during the evening, real prime-time viewing. Unfortunately, the seeing was poor most of the evening, compounded by a heavy haze, which severely dimmed Jupiter.
To make the tiny shadows easier to see, I used approximately 160x on the 6" and ~110x on the Telemator. 160x was pushing it severely, but occasionally the seeing would improve and details would pop out. I used the same binoviewer with barlow on both telescopes. The barlow gives approximately 3.25x and I used a pair of 25mm Zeiss eyepieces. Telescope magnifications are rounded off for convenience. I should measure them accurately one day, but I haven't gotten around to do it.
Io's shadow sat right on top of NEB, which made it difficult to see in the Telemator, because of the poor seeing and dim image. Both Io and Europa were completely invisible on the disk of Jupiter. Only once Io were close to the edge could I see it clearly, but this is not unusual.
The shadow of Europa only hit Jupiter in the middle of the session. It was *just* above NEB, making it a little easier to see. Had it been centered on the NEB, I'm not sure I could have seen it in the Telemator. As it was, it was difficult enough already. It was plain and easy in the 6".
Strangely, the seeing suddenly improved markedly, and although not perfect by any means, was suddenly good enough to allow some good details to be visible in the 6" and the shadows much more certainly in the Telemator, although Europa's shadow was still very difficult. In the 6", SEB now split in two halves, each mottled and broken up in many tiny parts. NEB was partially split by a very thin band, but was smoother than SEB. The equatorial zone sported mottling and hints of festoons.
When Io moved out from the disk, I observed it with the 6". It's quite fun to watch, as it happens surprisingly rapidly. It takes only ten minutes or so. Once it was just outside the disk, separated by a hair of blackness, I went over to the Telemator and compared the views. I could not see a difference in apparent size between Io and Jupiter in the two instruments. I compared with the tiny, black separation, which was also evident in the Telemator, as well as with the width of the NEB. In both the 6" and the 63mm, the dimensions appeared the same. This proves to me, that even a 63mm shows the true size of the Jovian satellites.
During the evening, thick haze came and went several times. After the spell of good seeing, thick haze moved in once more and the seeing went back down. I turned my attention to the east, where the haze had not yet reached, and looked at M13 with the 6" and an 11mm ES82. The view was superb. Very dark background and pinpoint stars to the edge of the field. M13 was resolved in hundreds of faint stars, arranged in long, curved chains. NGC 6207 nearby was also visible.
After this, the haze started to thicken once more and I decided to call it a night. Despite the mediocre conditions, it had been quite a nice session.