I hope this helps explain how to get closeups of the International Space Station and Solar transits.

TThe technique for the closeups is to point the telescope at a point the ISS is predicted to pass through. I set the camera on high burst rate (6.5 fps is the fastest on my Canon 40D) JPEG (not RAW as the buffer fills up too quickly. For short sequences RAW can be fine but make sure to leave plenty of time for the buffer to be written to the CF card before removing the card!) at 1/1000 of a second exposure at ISO 1600. As the ISS enters the field of view of the finder' date=' then set the burst going and stop when it leaves. There are typically 3 shots with the ISS in the frame when overhead but I got 4 on one pass as I (coincidentally) had the camera oriented diagonally to its path. Quite a bit of the structure such as the various modules, support trusses and solar panels are clearly visible.

To find out where it is going to pass through, the approach I use is to use Heavens Above ([url']www.heavens-above.com/) or Calsky (calsky.org/) to find a star the ISS is going very close to and tracking on that (HA has stars to about mag 6, Calsky much fainter). With a GOTO scope I don't need to use a star but get coordinates from Calsky and go to that coordinate and wait. Clearly focussing and seeing are now the limiting factors in how good an image one can get but if you can focus on the moon, a planet or a bright close double star (eg Castor) to get a sharp focus.

With a GOTO scope one problem is aligning it whilst still twilight (which is usually the conditions for an evening pass) even if the pass itself is in the dark. Usually there are not enough bright stars visible in the twilight to accurately align and then ensure the scope is properly polar aligned: there often is not enough time.

If you have enough time to get a good alignment, then you can enter the coordinates extracted from Calsky.org to get very close to the passthru point. Without properly polar aligning, there can still be sufficient drift that I had to re-enter the coordinates in the scope a couple of minutes before the pass just so I could be sure the scope would still be pointed at the right area.

This works fine for a DSLR like mine with a 30'x20' FOV (on my EdgeHD 925 scope). I would like to try with my 640x480 CCD camera but that has such a narrow FOV that I can't be confident the ISS will actually pass through. I'll try again when there's a prediction of a very close pass to a bright enough star AND I have time to actually align very accurately.

For the shots of ISS passes across the Sun. For these, aligning isn't the problem but knowing when it's coming through when you can't see it. For these use a GPS and start the burst about 1s before the predicted transit and stop about a second after (the transits are usually over in less than a second). Using RAW is possible for a sequence this short (buffer on the 40D holds 16 shots so about 2.5s worth at 6.5 fps) but make sure you let the buffer flush before taking the card out! 1/1000s or 1/1250s at ISO 1600 is about right for these shots (with a solar filter on the scope).

Some examples up here: International Space Station - a set on Flickr