This document provides an introduction to astrophotography and discusses why people photograph astronomical objects even though they can be viewed through a telescope. It explains that Hubble space telescope images inspired many people to try astrophotography. It also discusses the equipment needed like DSLRs, webcams, and telescopes mounted on equatorial tracks. The document provides tips for capturing various objects like the moon, planets, stars, galaxies and nebulae. It emphasizes taking many long exposure photos and stacking them to reduce noise. Finally, it showcases some of the author's astrophotography examples and identifies common software used in processing.

1. Astrophotography
(A non-scary introduction, hopefully)
James Billings, March 2013

2. Why bother?
Why not just look through a telescope and appreciate
the beauty of the heavens? Why do you need to
photograph it?!
It’s all Hubble’s fault…

3. What Hubble sees

4. What you see

5. • I don’t have a telescope!
• OK, I bought a telescope.
– Using your DSLR
– Using a webcam

6. I don’t have a telescope!
No problem, as long as you have a
tripod and shutter release, exposure
times are normally quite long...
Some examples…

7. Make the sky part of the picture
16mm f/3.5, 30s @ISO-400

8. Use brighter night-sky objects
18mm f/4.5, 8s @ISO-400

9. Zoom in!
300mm f/11, 1/4s @ISO-200

10. Try capturing satellites…
30mm f/4, 25s @ISO-400

11. Rare events…
35mm f/6.3, 25s @ISO-400

12. Try to capture the Milky Way
16mm f/3.5, 30s @ISO-1600

13. OK, I bought a telescope…
Using a DSLR on a telescope
Challenges:
– Light pollution
– The moon
– Long exposures
– Accuracy of mount
– Wind
– Pesky Satellites!
80s @ISO6400

14. Easy (ish) – the moon
1000mm f/1, 1/1000s @ISO-200

15. Harder - fainter objects
Galaxies Nebula Star Clusters

16. Problems
Planet earth rotates. This is NOT helpful.
We use an Equatorial
Mount to counteract
the rotation of the
earth.
Even then, we’re
limited:
• Alignment
• Worm error
• Stability

17. A single photograph
1000mm f/1, 69s @ISO-1600
But we want this:

18. Traditional processing
More detail, but horrible noise. We need to increase signal > noise.
Multiple exposures help as noise is random, subject is consistent.

19. Time for a demo…

20. End result
Adjust luminance and RGB levels.
“Beautify” in photoshop/lightroom/gimp etc.

21. Some more examples…

22. What about the planets?
• Planets are small, details are tiny, so we need
to increase our S/N even more (100s of shots)
• Our shiny DSLR is no use- the planet is too
small in the image
• We need a smaller sensor
= we use a webcam and record a movie!

23. Recorded video
Low resolution sample, up-scaled. Consumer cam (£10-£80)
Avi courtesy Jim Prior (http://www.flickr.com/photos/70350201@N03/ )

24. Time for a demo…

25. With an astro-specific camera
Better quality CMOS sensor for less noise, ~£240
(.avi courtesy Keith Townsend: http://www.flickr.com/photos/keith-t/)

26. Processing steps:
• Choose align-points
• Align, limit, stack
• Sharpen with wavelets
• Gamma/RGB adjustment

27. More examples. (mine )

28. The End
jowlymonster
JamesBillings
jmbillings
Registax (for planets): http://www.astronomie.be/registax/
Deep Sky Stacker (deepsky objects): http://deepskystacker.free.fr/english/index.html
Startrails (stack to make trails): http://startrails.de/
Heavens-above (satellite timings): http://www.heavens-above.com/
Thanks to Keith and Jim for the planet .avi files.