Photographing the Night Sky Lecture

1. Photographing the Night SkyRichland Public Library LectureNovember 15, 2012 Scott Butnerhttp://www.scottbutner.com/

2. What I’ll Cover • Introduction • What you’ll need to take night sky photos • Some camera basics • Shoot the moon! • Shooting the stars and the milky way • Catch a falling star • The northern lights? In Washington?! • Useful resources

3. Introduction

9. What you’ll need

10. Essential equipment • A camera with the following: • Manual control • A [wide angle] lens of f/2.8 or faster • Usable ISO of 1600 or higher • Remote release or self timer • Tripod • Flashlight • Backup flashlight • Appropriate clothing

11. Scouting locations • Scouting locations ahead of time is VERY important • Finding safe parking/ingress/egress and noting hazards • Finding good terrestrial objects • Noting power lines, road signs, other easy to miss visual impediments • Take notes! Note mileposts, landmarks, etc.

12. Finding dark skies • Dark skies are increasingly hard to find in our region • Typically need 30-40 miles from medium sized metro area to find reasonably dark skies • Clouds, dust, haze will exacerbate this • Localized light sources can often be incorporated or obscured

14. A few words about safety • Think ahead for safety! • Park well off the road • Scout ahead if possible • Wear “safe shoes” • Always have a backup light • Be aware of your surroundings

15. Some camera basics

16. The Bucket of Light ISO Shutter speed f/stop

17. ISO – How big is the bucket? • ISO is a measure of how sensitive the camera is to light • The higher the number, the less light is needed • But high ISO ratings also generate more noise (grain) ISO 3200 ISO 200 ISO 400

18. f/stop – How big is the hose? • f/stop is a ratio between the lens opening and focal length • The smaller the number, the more light it allows in • For most night photography, wide f/stops (f/1.4-f/2.8) are essential Typical f/stops: f/2.0f/2.8f/4f/5.6f/8f/11f/16f/22

19. Shutter speed – How long does the water flow? • Shutter speeds tell us how long the camera allows light to hit the film/sensor • MOST night photography requires long exposures (> 1 second) • Photographing the moon is a big exception

20. Putting them together • Different combinations of ISO, f/stop and shutter speed produce the same amount of light – but not necessarily the same results • 3200 ISO @ f/4, 30 sec • 3200 ISO @ f/1.4, 4 sec • 1600 ISO @ f/2.8, 30 sec

21. Some “typical” exposures • Milky way, rich star field • 1600 ISO, 30 sec @ f/2 • Bright stars, planets • 1600 ISO, 15 sec @ f/2-2.8 • Moon • Full: 200 ISO, 1/500 sec @ f/8 • Half 200 ISO, 1/125 sec @ f/8 • Crescent (highly variable!) • Lightning • 400 ISO, f/5.6-8, timed for flash*

22. Shooting the moon

23. Tips for shooting the moon • The moon is both the easiest and the toughest of night sky objects to shoot • Highly variable (but predictable) brightness • Very narrow range of opportunities to capture “optimal” shots • Dramatic “big moon” photos require big lenses

29. Shooting the stars and milky way

30. General night sky tips • In general, find the darkest, “cleanest” skies you can – not easy these days! • Be aware of moon phases. Too much moonlight hurts • Clouds can be good picture elements but amplify any light issues • Try to include some foreground elements for scale, dramatic relief

32. Tips for photographing stars • Modern cameras can disclose detail you’d never see with naked eye • Find the sweet spot for getting point-like stars • Very wide or fisheye lenses – 30 sec • Moderate wide angle – 20 sec • “normal” lens – 10 sec or less • Apparent motion greater as you move away from celestial pole

36. Making star trails

37. Making star trails • Star trails can provide a dramatic way of showing the earth’s motion • But long exposures demand a very dark sky! • 7-10 minutes is about the shortest exposure that makes sense • Effect varies with focal length and distance from celestial pole • StarTrails software can greatly simplify the job!

39. Photographing meteors

40. Tips for shooting meteors • Frequency of meteors is less important than brightness/duration • Lyrids, Taurids both known for producing bright fireballs • Use the highest ISO, widest f/stop you can muster • Be sure field of view extends 20-30 degrees beyond the radiant • Best strategy is to use lots of moderately long exposures and hope for the best

41. Key meteor showers • Orionids – THIS WEEKEND! • Geminids – December 13-14, 2012 • Quadrantids – January 3-4, 2013 • Lyrids – April 21-22, 2013 * • Perseids – August 12-13, 2013 * • Orionids – October 20-24, 2013 • Taurids -- Nov 4-6, 2013 • Leonids – November 17-18, 2013 *

44. Northern Lights

45. Tips for northern lights (aurora) • Northern lights are not common in our area, but do occur several times/year • Usually prefaced by 24-48 hours of warning • Require a very dark northern horizon • Exposures comparable to that for milky way (e.g., 20-30 sec, f/2.8, ISO 3200) • Can disclose detail not seen by naked eye

48. Next year’s comet • Comet ISON due to be visible in late 2013 • Projected to be brighter than full moon, visible during daylight hours • Potential for a once in a lifetime sight! Photo of Comet Lovejoy by Luis ArgerichUsed under Creative Commonshttp://www.flickr.com/photos/lrargerich/7394541294/

49. Some handy resources • Handy apps • TPE (The Photographer’s Emphemaris) • Moon Phase calendar • StarTrails.exe • Web sites • http://www.wunderground.com/radar/radblast.asp?ID=PDT&type=N0R • http://www.gi.alaska.edu/AuroraForecast/NorthAmerica/2012/11/13 • http://www.skyandtelescope.com/observing/ataglance • http://www.spaceweather.com/