I have just made my first attempt to photograph the International Space Station, and I clearly need to improve my technique. Here are the details:
- Body: Canon EOS-M (1)
- Lens: EF-M 55-200mm at 200m, f/6.3
- ISO: 400
- Exposure bias: -1EV
With AV priority, this gave:
- Exposure time: 2 sec
During the two-second exposure, the ISS obviously moved along quite a bit, but I was surprised that the blurred image was not uniform, but intermittent, as if something had been flashing at around 10-15 hertz.
Here's an 800x800 crop of the (3456x5184) image; the ISS moves right to left:
Clearly this is the sort o photo I wouldn't hope to take again, but I'm curious; can anyone tell me what might be going on here? Is this some kind of cyclic process in the sensor or processor?
BTW, I'm reasonably certain this is the ISS and not something else, as it appeared at the right time, positioned correctly relative to the moon, and with the trajectory I expected.
A note on focus:
In his comment, @MichaelClark rightly draws attention to my focussing -- another aspect that left a lot to be desired.
The photo was taken with manual focus, and with image stabilisation disabled. As I knew the ISS would be moving fast, I tried to pre-establish focus by using the Moon. The ISS was about 1350km from me, and I assumed (perhaps incorrectly?) the Moon's infinity to be a good enough approximation.