Shooting the Night Sky
The most common photographic subjects in the night sky, other than the Moon, are the Milky Way, and Star trails.
When you photograph the Milky Way you are shooting a type of image called a "star point". Most of the discussion below applies both to shooting star points, and shooting the Milky Way.
1. You need a dark sky. If you live in a city you'll need to travel well outside of it before shooting. Even small cities can ruin a good night sky image. For example, the White Pocket is over twenty miles west of Page, Arizona but the glow of Page is still evident if you shoot the eastern sky from the White Pocket.
2. The Milky Way is largely in the southern sky. Here's a shot taken at the White Pocket facing south. There were some clouds near the horizon. The foreground was light painted with a flashlight.
3. The Milky Way photographs better in the summer months of June to September than in the winter. In the winter the galactic core is below the horizon in the northern hemisphere.
4. You need a cloudless sky or at least a sky that is clear in the direction of the Milky Way. Ideally there should be little dust or haze. In August it often rains in the desert late in the day. This serves both to reduce haze/humidity and to wash dust from the air. In my opinion, August is an excellent time to shoot the Milky Way.
5. A moonless sky is desirable. You can use sunrisesunset.com to see whether the Moon will be out when you are shooting. If the Moon is out, its light will totally wash out the Milky Way.
6. You should shoot with a wide angle lens to capture as much of the sky as possible. 24 mm is a good starting point on a full frame camera. The lens should also be fast so that many stars appear in the final image. If you have an f2.8 lens or faster use it, although f4 will also work reasonably well. While you can compensate for a slower lens by raising the ISO, this will increase the noise in the blacks of the night sky.
7. 30 seconds is a good maximum exposure. If you go longer, the movement of the stars in the night sky will result in motion blur.
8. So my recommendation is: f2.8 or faster, ISO 400, 30 seconds for the exposure, at 24mm.
9. The foreground will normally be in silhouette unless you light it with a flashlight. The shape of the foreground is important but the color/contrast isn't when shooting silhouettes, Good foregrounds include arches, joshua trees, saguaro cactus, hoodoos, etc. Since you will be shooting wide open you may need to watch your depth of field but at 24mm you normally have good depth of field.
10. Bring a small flashlight so that you can check the settings on your camera, and be careful not to change them accidentally while you are getting ready to shoot.
11 .Scout your subject in advance; it can be very difficult to compose and focus in the dark, even with a flashlight. Mark the subject's position with a GPS. Mark your car's position with a GPS as well. On a moonless night navigation is very difficult; even things that are obvious in the daytime become impossible to find at night. For example, I did a night shoot at Toadstool Hoodoo last year and had difficulty following the trail back, even though the trail is very clear in the day and I had a strong flashlight.
12. A flashlight may work better than a headlamp, especially if there are bugs. I'd rather have bugs flying around my hands than my head!
13. Lighting the foreground can be done in two ways. The easiest way is to shoot two images, one at dusk and one at night. Combine them by taking the foreground from one and the night sky from the other. You'll need to be able to select the foreground in Photoshop to use this technique. After layering, adjust the exposure of the foreground picture to suit. There is a trick that can be used to help select the foreground. Create a third image when the sky is dark by light painting the foreground so heavily it is very overexposed. Use this image to create the foreground mask.
14. A flashlight or spotlight can be used to light the foreground. You can get various battery powered spotlights from amazon.com. These can be used to "light paint" distant objects. Try a one million candlepower torch to start. For nearer objects a diffuse flashlight can be used. When light painting, be sure to literally paint the foreground and make sure not to dwell in one place too long. Dwell somewhat longer on distant objects than nearer ones. Diffusers can be made from filter sheets used with studio or video lighting.
15. When the foreground can be easily selected I normally prefer the composite approach above to light painting. It has a higher success rate, and also often creates a side lit foreground. When you light paint you usually have a front lit fairly flat foreground. The following images were shot at Arches National Park The first uses the composite approach, the second, light painting. I prefer the side lighting in the first.
16. Light painting works well when you want to totally control the angle of light, want to better separate the foreground from the background, or have the background totally dark. This technique could be used at The Hooters in Coyote Buttes North. During daylight hours The Hooters blend strongly into the background which limits their appeal. At night a spotlight would effectively isolate them from the background. The Hooters face north so they make a good subject for star trails.
Shooting star trails is very similar to shooting star points. Because of the earth's rotation, each hour the stars in the night sky move by 15 degrees. In practice this means you'll need to have the shutter open for at least an hour to get a good star trail picture. If there is a full moon in the sky (or even a quarter moon) leaving the shutter open this long will result in most of the stars being washed out. So a work around was developed: when the Moon is out, leave the shutter open for at most 30 seconds and then immediately take another exposure. Repeat for at least the next hour or so. Over an hour you would get 120 exposures. There are many programs on the web that can then be used to combine the pictures into a single image, or even a video. The programs all work in the same way: they layer the images and combine them so as to always take the brighter pixels from each image in the result. I use the program startrails.exe which is freeware and can be downloaded from http://www.startrails.de/html/software.html . This program takes as input a collection of either jpg or tiff files. I use tiffs. I shoot in raw mode, adjust the exposures uniformly to get as many stars as possible and then covert the raws to tiffs which are then input to startrails.exe
.In the northern hemisphere star trails are best shot to the north. This generates very nice circles about the North star which can be viewed as an extension of the Earth's axis. Shooting to the east or west will generate long arcs, and shooting to the south (which should be generally avoided) will generate flat lines or very wide arcs.
The North star always points to true north, as opposed to compasses which point to magnetic north. To shoot effective star trails you need to be able to find the North star. First locate the Big Dipper which most people can easily do. Then extend the outer edge of the dipper as follows
The brightest star in the Little Dipper is the North star.
When shooting star trails use the same rules as for shooting star points: shoot wide (24mm or wider if possible), f2.8 or faster, ISO 400, and 30 seconds maximum exposure if the Moon is out. Shoot for at least an hour beginning at least 60 minutes after sunset and ending at least 60 minutes before sunrise. Shoot in continuous mode, or use a remote timer to get the necessary exposures. Test focus and exposure carefully before beginning your series.
Shooting towards the north produces the best star trails. Good subjects include the north entrance to The Wave, The Second Wave, Sand Cove, The Hooters, and Fatali's Boneyard, all of which are best shot to the north or northwest! The Temples of the Sun and Moon in Capitol Reef are also good subjects. Here is a sample image, the Temple of the Moon is in the foreground.
This page was last updated 1/16/2012