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:
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….
So, my top tips are:
- Use a finder that is precisely aligned – I use a Telrad;
- Before the pass focus the scope/camera until you are bored of focusing, using a star and a Bahtinov mask;
- Use a cable release
- Set maximum ISO
- Try a range of exposures during the pass.
- Get most frames when the ISS is at high elevation.
- Set the mount friction to allow a smooth motion.
Have a go!