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Friday, 6 July 2018

Astronomy: First attempts with a Canon EOS 550D and EF 75-300mm lens

And now for something completely different!

What does Satellite DX and Astronomy have in common?

You spend quite some time looking at the sky...

While considering the purchase of a telescope for astronomy, it crossed my mind that I should first check out what could be done with gear I already own.

So it happens that I have a Canon EOS 550D with two lenses, one being a EF 75-300mm lens, which is capable of zooming in considerably. In fact I can read the number plate of a car almost 1km away!

The following picture shows a truck that is 3km away from where I am shooting the picture:

With the naked eye, you can barely see the that there is a highway.
The picture clearly shows the highwat and a truck.
Zooming into the picture reveals even more information (upper right corner of picture above): you can almost read the road sign!

So I wondered: can the camera be used without further aid for some astronomy pictures?

The results were not great, but still better than I imagined.

Here is Jupiter and four of its moons:

Taking it even further, I tried to capture Saturn. The results were not great:

  • These pictures were taken with just the Canon EOS 550D and the EF 75-300mm lens.
  • The camera was mounted on a tripod (of course: even so, just touching the camera will cause vibrations that last 1-2 seconds and which blur everything in the field of view).
  • To take the picture, an IR remote was used, as pressing the button on the camera would cause too much vibrations.
  • Saturn could probably be improved, depending on the day of the year you try to take the picture. Aparently, the higher the planet in the sky, the better the picture.
  • The weather was not so good, there were clouds.
  • I live in a city so light polution is an issue.
  • This was my first attempt ever.
  • I now understand what chromatic abberations are: notice the purple halo around Jupiter and Saturn. This is due to the lense refracting red wavelength differently from blue wavelength. This is why it is better to do astrophotography with mirror based telescopes, instead of telescopes with lenses. Quite interesting!
  • I did see two satellites and probably what might have been the ISS (International Space Station . which is visible a moving dot), but I did not have enough time to try to take a picture. It takes some experience to handle the camera on a tripod at night...

This was really fun and interesting. I never saw Jupiter's moons live by myself and that was quite an amazing thing to see!

Will I get a telescope? Probably yes...

Update - 2018-07-07:

Tonight I tried again and was smart enough to change the camera's settings for better viewing.

Guess what: I could see Saturn with the ring! Not a NASA quality picture, but amazing anyway.

This picture kind of shows the ring, but the live view on the camera's LCD at 10x zoom allowed for a much better viewing. I think I should have put the camera to RAW picture mode, in order to avoid any JPEG compression.

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