I noticed, in checking over Stellarium late this afternoon, that not only was the ISS going to make a highly-visible pass a couple hours hence, it would be closely tailed by the Dragon Crew Capsule, I believe having recently separated from the station. I figured this was worth a shot in capturing both at once, even if it was going to be difficult to snag. The issue is, the ISS is small (from our vantage, anyway,) the Crew Capsule more so, requiring very high magnification, typically with the 2X teleconverter. But they’re also moving across the sky at a good clip, so a short shutter speed is in order. Those two don’t go together well, because the teleconverter reduces light by two stops, slowing the shutter speed. And the Crew Capsule isn’t very bright, so even boosting the ISO to maximum might not necessarily get the shutter speed low enough to reduce motion blur adequately and still get a decent exposure on the ships. Then there’s the whole path deal, being locked in tight with the tripod where the two craft would cross the frame, quite challenging at that high a magnification because it means a very narrow corridor, and finding and following the craft with the long lens was out of the question: by the time I locked the rig down for stability, the ships would pass from the frame, and doing it without locking the tripod would only induce motion blur. But I’d plotted the position in regards to two prominent stars, so I was game.
The sky wasn’t, though. Less than an hour before, while still in sunset twilight, there were some thin scattered clouds, little more than stains, which would only limit things if they were right where I was aiming. But as I stepped out the door about ten minutes before the two spacecraft would pass, the sky was almost completely overcast, the full moon only throwing a dull glow through the cover. Not a chance in hell, in other words.
So we have a color example from the earlier sky, because. Maybe next time.
