Star Gazing   4 comments

I went star gazing last night.  It was the first time in a long time I looked through my telescope, a rather sad admission to make.  The weather was clear and warm in the late afternoon, and so I loaded the van with my 8-inch Newtonian telescope, a cooler with drinks and snacks, and my photography gear.  Oh, and my dog came with.  This post will have a few photos, but I have already published several of my good ones in my post “Moonlight”.  Check that one out.

Mount Hood and the rising half moon from the summit of Larch Mountain in Oregon.

I had a good little time up on Larch Mountain, which is the closest place to my home where the stars are fairly bright.  It’s about 40 minutes away, on top of a 4000-foot mountain, and has a view of Mount Hood.  I had a nice time up there, but it only whetted my appetite, and now I have to get way out there to try for really nice photos.  Crater Lake is calling, as well as Mt Rainier.  I also am so hoping the Sun sends us another present; i.e., a big solar flare that causes aurorae at low latitudes.  It did this a few weeks ago, and I messed up big time not getting out to see it.  The Sun is active right now, and we get a few days notice of events, so I’m watching NASA’s website and keeping my fingers crossed.

I used to teach, and during that time I got into astronomy big time.  I bought the telescope, learned my way around the sky, and even became well-versed in astronomical principles (I had to because I taught a high school astro. class).  I spent a couple seasons at an outdoor school in what is probably Oregon’s best dark sky region, Wheeler County in the unpopulated eastern part of the state.  There, as an instructor, I had access to very good telescopes, and ran astronomy camps and classes.  Most importantly, the night sky was so spectacular that you could sometimes see your shadow on the ground.  And this was not from the moon, but from the Milky Way alone!

Now as a photographer I’ve been playing around with starscape photography.  This is normally defined as photos of the stars, aurora, etc. but with portions of the earthly landscape included.  Pictures of the stars and planets with no landscape?  That’s called astrophotography, something I also played about with during my teaching time.

I went but astrophotography is a one of those things that requires commitment in order to obtain excellent results (and excellent results are all I go for).  You need not only plenty of time and education on techniques and software, but you’ll need to buy a very expensive telescope (actually it’s the mount that is most expensive) plus a CCD camera.  All of this said, you can get pretty stunning astrophotographs with a simple “go-to” telescope of roughly half a thousand dollars, plus a digital videocam or digital camera with mount.

An eastern Oregon starscape features Venus and, on the horizon, Mercury. Several constellations are also visible, such as Orion the Hunter at left. The bright star peeking out of the clouds on the left is Sirius, the northern hemisphere’s brightest.

For starscape photography, you only need your digital camera (DSLR is preferred), a solid tripod and as fast a lens as you can afford.  An f/2.8 lens or faster will make a big difference, though you can start with an f/4 lens.  A wide-angle lens is almost a must as well, something on the order of 24mm or wider.  This setup will allow you to get star trails (those photos of many circles or arcs of light you see) as well as images of pinpoint stars (which I prefer).  With a timer remote, you can set up to take a time-lapse, which is very popular right now (I’m not too impressed with them though).

But you need to remember this: the stars (and planets, moon, sun) appear to move across the sky.  The earth, as everyone knows, rotates on its axis.  This means that you and your tripod and camera are always moving under the stars.   And so your long-exposure images have the potential to smear out or arc the stars, while the landscape below remains perfectly sharp (it’s moving too).  So here are some general considerations:

  • In addition to the above camera-related gear, you’ll need a flashlight (or two).  For seeing what you’re doing, you need a red flashlight.  Your night vision is super important to maintain, and a white light will reset your eyes so that you need to wait a half hour or more to get back your night vision.  Look at astro forums or you can get red cellophane from a party store and tape 4 or 5 layers of it over your regular flashlight.  Bring another light (with other colored cellophane?) for light painting.
  • Learn about the night sky.  As with any photography, the more you know about your subject, the better your pictures.  Get a star chart and take it out with a red flashlight to get familiar with constellations and how they move through the sky.  Bring binoculars (or telescope) to get a close look at what you are photographing.
  • Find the darkest and clearest sky you can get to, well away from light pollution.  You simply have many more options if the night sky is pristine.
  • Regarding the landscape,  strong elements like a fascinating old building or monument, a (very) interesting tree or rock, or a spectacular mountain range are all worth considering.  In my opinion, star trails only work well if the foreground is very striking, and should not be used more than occasionally.
  • You will normally be focusing at infinity, at wide open aperture or stopped one down.  To focus, either autofocus on a distant mountain then turn your AF off, or if there isn’t enough light, find a very bright star or planet and manually focus on that.  You can use live view as well, with the ISO temporarily cranked up to a moderately high number.
  • Any exposure of over 15 seconds will have at least some evidence of movement in the stars (or moon).  If you have a very wide angle, say 16 mm, you can get away with 20 or even 25 seconds.  Also, the closer to north (or if in the southern hemisphere, south) you point your camera, the less movement you will notice.
  • If you have no moon and if the landscape below is not very reflective, you will have a very dark image if you shoot at 20 seconds or shorter shutter speed.  You should shoot either wide open (lowest f number) or one stop down (next higher number), and this helps but will not get you a bright image below 20 seconds.  That is, unless you raise your ISO (see next point).
  • Digital noise can be a problem.  First of all, noise is most obvious in dark areas, and you have almost all dark area in a starscape.  Second, the longer the exposure, the more noise.  Third, raising your ISO, say to 800, can give you a bright enough image at less than 20 seconds exposure time.  But the higher your ISO, the more noise.
  • Final noise point: I recommend you try raising your ISO, which could mean only 400 if you have a camera that does not handle noise that well, or even 1600 if you have, say, a Nikon D4 or Canon 5D III.  Then use noise reduction software, either Lightroom or a plugin like Topaz Denoise.  Your camera might have a long exposure noise reduction setting.  Skip it.  It will just double the time you have to wait for the camera to finish, and it doesn’t do as good a job as post-processing software does.
  • You basically have two choices with landscapes.  Either include a simple, recognizable silhouette (a bare tree is the classic – overused? – example) with a bright starry sky (or moon) in the background, or illuminate the foreground.  If the foreground is close enough, you can “paint” with a flashlight or LED during the exposure.  You can also let nature illuminate it for you.  A partial moon can do the job nicely, but you will need dark and very clear skies in order for the stars to not be washed out by the moon.  Experiment; even the full moon can work if you shoot in the opposite direction from it.
  • I’m not discussing things like stacking multiple images in Photoshop, and other post-processing techniques.  Sometimes photographers get these spectacular images with millions of stars, and they’ve stacked images so that stars are repeated.  I avoid this, because it’s phony (I want constellations to be recognizable).  You can stack and get stars that are not visible with the naked eye, which is a little more real I suppose.  You can google this and get some tutorials.  But one thing I will mention is that you can composite two photos, one exposing for the sky, the other for the landscape (see last two points).
  • You can get around the shutter speed limitation by moving with the stars.  You will need a motorized mount to do this, either a tracking telescope or an add-on to your tripod.  Unless you are good at making things, I recommend either picking up a used telescope that tracks (and a piggyback mount for your camera), or buying the fairly new Vixen Polarie.  I just bought this little gem and will soon be shooting with it.  It is a compact, add-on mount for your tripod, and runs on only two AA batteries.  It tracks the stars for you, at both full and half-speed.  It allows you to keep the stars pinpoint sharp over longer exposures, which gives you a brighter and better image.
  • But if you are tracking, you now have the landscape blurred.  So you need to either try tracking at half speed (a great option on the Polarie) or composite two images: one tracking and one with the Polarie switched off.  The only drawback to this amazingly compact unit that I can see is that it cannot handle more than about five pounds.  All depends on not only your camera’s weight, but also your lens and your tripod head.  Note that you will need two tripod heads to use the Vixen.

So this is my admittedly opinionated take on photographing the night sky.  While I’ve tried to lay out the basics, there is no substitute for getting out and experimenting.  Remember to dress more warmly than you’d think would be necessary, and take some snacks and a thermos.  Motivation is a little more difficult to maintain in night sky photography than with normal landscape photography.  The idea is to have fun and to learn more about the night sky.  Good luck!

The total solar eclipse of 2009. This was right after I finally bought a nice DSLR, and I did a cruise in the north Pacific to view this. This is called the “diamond ring” effect. Total solar eclipses are one of Earth’s greatest spectacles.

The annular eclipse of May, 2012 was visible from northern California. I consider solar eclipses to be night sky photography, even though they occur in daytime.

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4 responses to “Star Gazing

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  1. Pingback: Blog feature: MJF Images | Kan Walk Will Travel

  2. Thanks for the post for posting “Star Gazing ”.
    Iwill really be back for much more reading through and
    commenting in the near future. Many thanks, Jenny

  3. Pingback: Shooting Stars at Zion National Park «

  4. thanks for posting

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