Photographing the night sky

In Guides, Photography, Travel, Tutorial

The Milky Way, a lit Airstream, and somebody opening a car door...

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Living in densely populated areas, many readers often miss the incredible majesty of the night sky.  Sure, stars can be seen above the city skyline, but light pollution really drowns out the incredible spread that hangs above our heads each night.

Fortunately when traveling to remote locations there are opportunities to create stunning images of the night sky.  Traveling through many of the National Monuments in the Southwest will afford photo buffs opportunities they couldn’t even dream of “back home.”  Camping on the North Rim of the Grand Canyon, visiting the Vermillion Cliffs, parking your RV near Vulture Peak…. Visitors will find themselves in truly “Dark Sky” areas, and the photo opportunities abound.

Photographing Star light

There are two very standard approaches to photographing the night sky.  One involves very long exposures to achieve “star trails,” and the other involves very short exposures to freeze everything where it is (like the image at the start of this article).  Both techniques require higher end gear, a tripod, and a willingness to bump around in the dark as you setup your images.

There are a few suggested items that you should bring along to ensure that your star light photography comes across as dramatically as you want it to:

The Star Walk app for iPhone.  Shows you everything in the sky!
The Star Walk app for iPhone. Shows you everything in the sky!
  • Tripod:  A sturdy tripod with a head that locks into place is an absolute must.  Any jarring or bumping of the camera during your exposure can ruin your image in an instant.
  • Cable Release:  Yes, they still make cable releases for cameras.  In order to make certain that you are not bumping your camera or the tripod the cable release allows you to open your shutter a few feet away from your setup.  There are wireless cable releases on the market now, so if you want to get really fancy you can by all means.
  • Headlamp or Flashlight:  Shooting at night means you’re going to need to find your way around.  When you create your exposures you’ll want your light off, but while you’re navigating and setting up you don’t want to walk into a cactus or off a cliff.  LED headlamps are very helpful.
  • Star Guide or Star Guide App:  Outdoor outfitters, some camera shops, and many park service offices sell star charts.  These will help you get your bearings on what you’re shooting.  With the latest mobile technology you can also find great Star Guide apps like “Star Walk” for the iPhone.  These apps will show you exactly what you’re looking at, making setup for your photography extremely simple.
  • Fully Charged Battery:  Night time photography requires your camera’s shutter to be open much longer than standard photos.  You could be shooting a single frame anywhere from 20 seconds to several hours.  With the shutter open that long and the camera chugging away recording light information you will burn through a battery quickly.  So make sure it’s fully charged, and maybe have a spare on hand just in case.
A quick star trail photo above the author's Airstream
A quick star trail photo above the author’s Airstream

Star Trails

Shooting star trails is something you can do with any level of DSLR.  The most common setup is to point your camera toward the North Star to really get a swirl of stars above whatever subject you choose in the foreground.  On many of today’s DSLRs photographers have fully Manual settings, or even a “Bulb” mode.  In the case of the latest Canons, bulb mode is available for night time photography.  In bulb mode you can control how long your shutter is locked open with your cable release.

Prior to shooting your star trails you’ll need to set your focus.  At night time this often means manually focusing as the auto focus features on many cameras don’t do well in the dark.  If the desired image contains something in the foreground your flashlight can come in very handy.  Light up the object (tree, mountain ridge, Airstream) with your flashlight and then set your focus accordingly.

Creating compelling star trails is time consuming.  While the earth is rotating pretty fast, it still takes a while on a long exposure to show the star trail motion.  And that long exposure is what allows light information into your camera.  In order to make sure you don’t “blow out” the image, star trail photography requires a low ISO setting.  In the case of the Airstream image here it was a 50 minute exposure at ISO 100 and f/8.0.  The windows of the Airstream are still completely blown out, and the aperture should have been set to something like f/14 if we wanted more detail in the windows.  There’s a very simple rule for doing star trails:

The higher the ISO, the shorter the exposure.  If you want to capture a full swirl of stars you’re going to shoot very low ISO (like 100) for a very long time.  Narrowing the aperture also allows for a longer exposure (let’s say f/14 for example).  For shorter exposures (like the Airstream) a wider aperture like f/8 did the job.  Of course, finding the right setup for your purposes takes some experimentation to be sure.  And with today’s digital cameras you can see your results instantly.

If you want to get the full circular swirl that you’ve seen in so many amazing night photos there’s a simple way to do it.  Point your camera toward the North Star, set your ISO as low as possible, and put your aperture somewhere between f/14 and f/22.  Lock open your shutter with your cable release and go read a book for 2-3 hours.  Come back to your camera later and close the shutter.  You’ll have that full circle pattern you were looking for.  If you got it wrong you can always try again tomorrow night.

The Milky Way above the Airstream.  24 second exposure at f/4.0 and ISO 6400!
The Milky Way above the Airstream. 24 second exposure at f/4.0 and ISO 6400!

Capturing the milky way

Capturing planets, still shots of the night sky, or the Milky Way above the landscape is something of “opposite land” from Star Trail photography.  Where we’re interested in extremely long exposures while shooting trails, shooting static objects in the night sky requires extremely “short” exposures (relatively speaking).  On average, you’re looking to have your shutter open from somewhere between 20 – 25 seconds.  In order to do that you’ll be changing a few things from your star trail setups.

Where star trails require a long time to follow the rotation of the earth and therefore require narrow apertures and low ISOs, shooting the Milky Way needs to be quick.  So we’re simply going to reverse our thinking.  Wide open apertures (f/1.4 or f/2.8) and high ISO to get the light information as fast as you can.

The Airstream Milky Way photo featured in this section is a great example of a short high ISO exposure.  The lens that was used is an f/4.0 wide angle.  I would like to have shot with a f/2.8, but my wide angle is as good as it’s going to be.  See, if I had shot at 2.8 I could have lowered the ISO setting to 3200 instead of 6400.  The higher your ISO is, the more noise there will be in your image.  Fortunately, post-processing software like Lightroom can help you deal with the noise after.

Since you’re shooting the wide open night sky with this setup, normally you will only need to set your focus to Infinity.  If you’re trying to shoot a foreground object close up, and you’re shooting with your lens wide open and focus on the close object you can be guaranteed that your background (the amazing sky) won’t be in focus.  Your foreground object will be.  Which is why it’s suggested that you move back a bit, set to infinity, and work from there!

Unlike star trails, shooting the Milky Way or other heavenly bodies won’t take so long.  That means you can really experiment with your images and dial in to the desired effect.  Bottom line?  Shooting somewhere between f/1.4 and f/4 (depending on your lens), ISO 3200 – 6400 (depending on your lens aperture setup), and shooting around 20 seconds.  From there you can totally experiment and see your results.

If you’re up for a full night of star light photography here’s an easy suggestion.  Shoot the fast images first.  Have your fun focusing on Mars, or a nebula, or the moon, and then setup for your long star trail photos and head into your tent / RV and take a nap.  Pretty easy, just don’t forget to come out and close your shutter at some point during the evening while doing the trails!

A short tutorial on post-processing your star light images

 

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