International Space Station

ISS Lunar Transit using a C90 and a Canon 700D. There is a video of the crossing on my channel. It was over in 2s!

ISS lunar transit.

Close-up view taking one of every three frames.

I managed to capture a lunar transit on 25th Nov 2018:

The ISS crossing the Sun on 15th August 2017. Taken using a C90 . I have taken a snapshot every 0.2s from the video file and merged them in PSP.

ISS_Mosaic_310716_Jenhams_PSP
Mosaic of 3 manual exposures of the ISS as it passed over on the 31st July 2016

ISS_Vega_310716_Jenhams
ISS taken on 31st July 2016 as it passed Vega, using a Samyang 14mm lens.

I tried to get a decent image of the ISS using my C90 for several months. The results were….varied.

This one is the best:

ISS_5th_April_2016_C90_2x_v2
The ISS taken through a Celestron C90 telescope on 5th April 2016, using a 2x Barlow and a Canon EOS. The exposure is 1/400s at ISO 1600

Previously I wasn’t using the barlow, largely because I thought it would make the manual tracking of the ISS even harder than it already was. The problem is that without the barlow, the 1250mm focal length C90 gave an image scale that was just too small and pixelated when the image was zoomed (and zoomed and zoomed).

And this was a good result at that image scale….

ISS
The ISS on 15th March 2016 using a Celestron C90 (without a Barlow). The ISO was 1600 and the exposure 1/320s

So, my top tips are:

  1. Use a finder that is precisely aligned – I use a Telrad;
  2. Before the pass focus the scope/camera until you are bored of focusing, using a star and a Bahtinov mask;
  3. Use a cable release
  4. Set maximum ISO
  5. Try a range of exposures during the pass.
  6. Get most frames when the ISS is at high elevation.
  7. Set the mount friction to allow a smooth motion.

Have a go!