Many people will argue that basic photography is relatively simple. Especially with advancements in DSLR and point-and-shoot cameras, all you really have to do is point at your subject and snap the picture. Of course, that doesn’t take into account proper composition (or the lack thereof), but that’s an entirely different topic.
Some techniques, however, are much more difficult to get right. One of these techniques is known as astrophotography, or taking pictures of the star-filled sky. It is imperative that you have manual control of your camera including shutter speed, aperture, and ISO control. Without these manual features, it will be very difficult to properly configure your camera for these night sky shots. You can learn more about the requirements in Night Photography Unlocked.
Equipment You Need
It doesn’t matter how steady you think your hand is, when you are talking about exposure times between 10 – 30 seconds or more, you need a tripod. It doesn’t have to be anything fancy, but a tripod is necessary to capture the stars properly.
You also need a camera with manual controls. You simply cannot expect an autofocus point-and-shoot camera to capture light this faint and far away.
You also need a wide aperture lens. Since you need so much light, f/2.8 seems to work pretty well for astrophotography. Using an ultra wide lens will also give you the depth of field you are looking for in your sky shots.
Although that is all that is absolutely required, theres plenty of other accessories you could use to further your shots. A polarizing lens could work well, but the exposure times would need to be even longer which then adds the complication of star movement to your photograph. Experimentation is the name of the game when it comes to astrophotography.
Long Exposure Photography teaches you some additional tips and tricks you can use for long exposure shots.
Pick a Good Location
One of the hardest things about capturing the night sky properly is light pollution. Since your shutter will be open for so long, it’s very easy to bring in light from cities that are miles away. If you really want to take good pictures of the stars, you’re going to have to get far away from the city and even then you still may have some light pollution present in your photographs.
In addition to figuring out where you want to take your pictures, you should also have a general idea of the various stars and constellations that you would like to photograph. Because these constellations can often be in different places throughout the night, do a little bit of research to figure out which way you should be pointing your camera for the best photo opportunities. There are plenty of websites that will tell you what part of the sky you should be looking at on a given night.
Getting as much light as possible to hit your camera’s sensor is the key to successfully photographing the stars. A high ISO, wide apertures, and long shutter speeds are all required to achieve the desired effect.
The exact settings you use will depend greatly on your area, how bright the stars are on a given night, and the presence of light pollution in the area. As a general rule, and ISO of 1250, an aperture of f/2.8, and an exposure of approximately 20 seconds usually works well.
Although you can increase the exposure time to approximately 30 seconds, anything more than that usually results in movement of the stars. Of course, creating star trails (as they are known in photography circles) is another cool photography technique. In this case, you would want exposure times somewhere around one minute to really capture the movement of the earth in relation to the stars above. But if you are looking for static star shots, 30 seconds tends to be about the maximum exposure length.
Taking star photographs always requires processing. Hopefully you saved your images in RAW format (if your camera allows for this) as the increased density of the uncompressed image will be useful to draw the stars out of the image.
The easiest thing to do is to break the photograph into two zones for processing. The sky should be one zone and any foreground should be a separate zone. If the shot is only of the stars you can skip this step. You can tweak each region separately to get the proper saturation and really see the stars in the picture without ruining the color saturation of the foreground.
You can use Photoshop to modify these pictures or you can use Adobe Lightroom. You can learn more about using Photoshop to process star pictures in Photoshop CS6 Essentials.
If you choose to use Lightroom,, check out The Ultimate Lightroom Experience.
Learning how to properly photograph the stars is a skill that takes a lot of practice to master. Once you have it down though, it is one of the most rewarding photo opportunities you’re likely to find. It won’t be long before you are looking for reasons to escape outside the city limits and find a nice, dark spot to set up your camera and start taking pictures of the night sky.