Photographing Star Trails

January 5, 2008

The heavens are one of my favorite Nature and Landscape photographic subjects. They're dynamic subjects, appearing to move through the frame of a long exposure, even though it is the Earth that is doing all the moving. I've been fascinated with night photography and the classic star trails photograph ever since I saw one of Galen Rowell's images titled "Star streaks over South Gasherbrum Glacier, Karakoram Himalaya" from Pakistan in 1989.

Location, Location, Location

Of course in order to do a classic star trails photograph, one really has to be in a place dark enough, lacking all those extraneous lights found close to the cities in which so many of us live. The Grand Canyon in Arizona is such a place, and since we're now back from our photographic trip there it's time to write about star trails, and the last two photographs of my 2007.

For those not lucky enough to have been someplace really dark before, it's hard to grasp just how majestic the heavens really are at night. The Grand Canyon is one of the darkest places in the United States and thus excellent for night time star observation. Bryce Canyon is better, and close to home in San Diego, the Anza Borrego desert is also a great spot. Since I'm from the Southern Hemisphere, New Zealand (which has some fantastic spots), I'm not as familiar with finding all the constellations up here as some of you local readers are even though I've obviously heard of them. So my wife and I bought a star finder so she could clue me in on where everything is, an excellent purchase that really will improve your understanding of where and how to find all the major constellations.

Equipment

Anyway, back to photography. Last time I shot star trails I was equipped with a Hasselblad SWC film camera loaded with Fuji Velvia in Bryce Canyon, however, this time I intended to try digital with a Canon 5D with the external grip attached so as to squeeze more battery life out of the camera. The grip takes two BP-511A batteries, so is a great boost to night photography as well as improving the handling for my photojournalism usage. Using my 17-40 f/4L lens and cable release on my trusty gitzo tripod, I was ready to brave the cold of the South Rim at night. I'm a huge fan of wide and ultra-wide angle lenses, both in photojournalism and landscape photography, funnily enough for the same reason: they tell more of the story. In the case of the night sky, there really is a huge story to tell, so the wider the better for me. I ended up taking two frames, so given the freezing temperatures I wasn't going to make either of those images really long exposures, just keeping them to around 30 - 45 minutes each. The batteries will hold up for at least a 1.5 - 2 hour exposure on the 5D with the external grip. There's no need to boost sensor gain here, so ISO 100 is perfectly fine, and again you can use whatever aperture you wish stopping down if you have close foreground subjects.

Viewfinder Eyepiece Cover and Access Lamp

As a technical note to other digital camera users, I set long exposure noise reduction off. It didn't appear to be necessary, with no hot pixels visible during my preparatory testing. Long exposure noise reduction also drains more life from your battery as it requires an equal length dark frame exposure to your main exposure. Ouch! So I would turn it off first. I also didn't place the rubber viewfinder Eyepiece Cover which turns out to be necessary, at least for Canon users. It's really only necessary since the 5D, and others, have a nice "helpful" orange light, called the "Access Lamp" in the user manual, on the rear of the camera that lights up to let you know the camera is reading or writing to the flash card. This is to warn you not to open the SD Card Slot while data is being written to the card. For some reason this lights up during a long exposure when data should be being written to the internal buffer. This same orange light also provides a source of illumination to leak into the frame through the viewfinder during said exposure. Fortunately it shows up as a tiny glow on the right edge of your frame, so it is easily cropped out, but it something to watch out for and not something I'd ever had to worry about with film cameras.

Abstract Star Trails

First was an abstract image. I framed closely on the Constellation of Orion the hunter setting the focal length to 40mm to remove any foreground details and opened the shutter. After star gazing and exploring the constellations with the naked eye for a half hour, I closed the shutter and voila, a nice abstract star trails image. I've gone with a black and white palette for this image.

Orion the Hunter, Abstract Star trails, Grand Canyon National Park.

Classic Star Trails

Next, and lastly, was my classic star trails image. The is the one we'd come out to get on New Years Eve. Finding a nice part of the rim with some foreground interest to tie the night sky to the land, I composed and opened the shutter for what would be about a 45 minute exposure. Again with auto noise reduction set to off. The noise characteristics of modern digital Cameras like the 5D and the 1D series and now the Nikon D3 make noise reduction not really necessary for your classic star trails image.

Star trails over the South Rim, Grand Canyon National Park.

Conclusion

It's really not that difficult to capture wonderful star trails images, just requiring some basic knowledge of the night sky and locations to pick a nice dark place away from city lights, a tripod and cable release and a decent dose of perseverance to wait it out. Oh, and warm clothing if you're doing this someplace cold during the winter time! So what are you waiting for? Really, get out there and give it a try...