Astrophotography(A non-scary introduction, hopefully)                                        James Billings, March 2013
Why bother?Why not just look through a telescope and appreciatethe beauty of the heavens? Why do you need tophotograph it?...
What Hubble sees
What you see
• I don’t have a telescope!• OK, I bought a telescope.  – Using your DSLR  – Using a webcam
I don’t have a telescope!No problem, as long as you have atripod and shutter release, exposuretimes are normally quite lon...
Make the sky part of the picture16mm f/3.5, 30s @ISO-400
Use brighter night-sky objects18mm f/4.5, 8s @ISO-400
Zoom in!300mm f/11, 1/4s @ISO-200
Try capturing satellites…30mm f/4, 25s @ISO-400
Rare events…35mm f/6.3, 25s @ISO-400
Try to capture the Milky Way16mm f/3.5, 30s @ISO-1600
OK, I bought a telescope…              Using a DSLR on a telescopeChallenges:  –   Light pollution  –   The moon  –   Long...
Easy (ish) – the moon1000mm f/1, 1/1000s @ISO-200
Harder - fainter objectsGalaxies     Nebula    Star Clusters
ProblemsPlanet earth rotates. This is NOT helpful. We use an Equatorial Mount to counteract the rotation of the earth. Eve...
A single photograph1000mm f/1, 69s @ISO-1600                        But we want this:
Traditional processingMore detail, but horrible noise. We need to increase signal > noise.Multiple exposures help as noise...
Time for a demo…
End resultAdjust luminance and RGB levels.“Beautify” in photoshop/lightroom/gimp etc.
Some more examples…
What about the planets?• Planets are small, details are tiny, so we need  to increase our S/N even more (100s of shots)• O...
Recorded videoLow resolution sample, up-scaled. Consumer cam (£10-£80)Avi courtesy Jim Prior (http://www.flickr.com/photos...
Time for a demo…
With an astro-specific cameraBetter quality CMOS sensor for less noise, ~£240(.avi courtesy Keith Townsend: http://www.fli...
Processing steps:•   Choose align-points•   Align, limit, stack•   Sharpen with wavelets•   Gamma/RGB adjustment
More examples. (mine )
The End                                  jowlymonster                                  JamesBillings                      ...
Upcoming SlideShare
Loading in …5
×

Cambridge Darkroom - Stars in our eyes by shooting stars in the sky at night

347 views
253 views

Published on

These are the slides accompanying the 28th of March 2013 Cambridge Darkroom meetup: http://www.meetup.com/CambridgeDarkroom/events/106902682/

James Billings, a photographer with a penchant for all things starry, guided us through three different types of Astro Photography:
- Wide field with just a camera
- Planetary images with a webcam
- Deep-sky images with a DSLR

With plenty of examples included.

0 Comments
1 Like
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
347
On SlideShare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
9
Comments
0
Likes
1
Embeds 0
No embeds

No notes for slide
  • What can we do without any special equipment?
  • Iridium flares, ISS. Predict with Heavens-above or various phone apps.
  • NLC’s – formed very high up from ice crystals. Rare but on the increase – due to climate or more observations?
  • Take several shots to find sharpest, use fast exposure. Atmosphere is actually very wobbly.
  • Jim’s example, upsized
  • Cambridge Darkroom - Stars in our eyes by shooting stars in the sky at night

    1. 1. Astrophotography(A non-scary introduction, hopefully) James Billings, March 2013
    2. 2. Why bother?Why not just look through a telescope and appreciatethe beauty of the heavens? Why do you need tophotograph it?! It’s all Hubble’s fault…
    3. 3. What Hubble sees
    4. 4. What you see
    5. 5. • I don’t have a telescope!• OK, I bought a telescope. – Using your DSLR – Using a webcam
    6. 6. I don’t have a telescope!No problem, as long as you have atripod and shutter release, exposuretimes are normally quite long... Some examples…
    7. 7. Make the sky part of the picture16mm f/3.5, 30s @ISO-400
    8. 8. Use brighter night-sky objects18mm f/4.5, 8s @ISO-400
    9. 9. Zoom in!300mm f/11, 1/4s @ISO-200
    10. 10. Try capturing satellites…30mm f/4, 25s @ISO-400
    11. 11. Rare events…35mm f/6.3, 25s @ISO-400
    12. 12. Try to capture the Milky Way16mm f/3.5, 30s @ISO-1600
    13. 13. OK, I bought a telescope… Using a DSLR on a telescopeChallenges: – Light pollution – The moon – Long exposures – Accuracy of mount – Wind – Pesky Satellites! 80s @ISO6400
    14. 14. Easy (ish) – the moon1000mm f/1, 1/1000s @ISO-200
    15. 15. Harder - fainter objectsGalaxies Nebula Star Clusters
    16. 16. ProblemsPlanet 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. 17. A single photograph1000mm f/1, 69s @ISO-1600 But we want this:
    18. 18. Traditional processingMore detail, but horrible noise. We need to increase signal > noise.Multiple exposures help as noise is random, subject is consistent.
    19. 19. Time for a demo…
    20. 20. End resultAdjust luminance and RGB levels.“Beautify” in photoshop/lightroom/gimp etc.
    21. 21. Some more examples…
    22. 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. 23. Recorded videoLow resolution sample, up-scaled. Consumer cam (£10-£80)Avi courtesy Jim Prior (http://www.flickr.com/photos/70350201@N03/ )
    24. 24. Time for a demo…
    25. 25. With an astro-specific cameraBetter quality CMOS sensor for less noise, ~£240(.avi courtesy Keith Townsend: http://www.flickr.com/photos/keith-t/)
    26. 26. Processing steps:• Choose align-points• Align, limit, stack• Sharpen with wavelets• Gamma/RGB adjustment
    27. 27. More examples. (mine )
    28. 28. The End jowlymonster JamesBillings jmbillingsRegistax (for planets): http://www.astronomie.be/registax/Deep Sky Stacker (deepsky objects): http://deepskystacker.free.fr/english/index.htmlStartrails (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.

    ×