The night sky is brimming with the brilliant light of distant galaxies and stars. Those pinpricks of light stand out in breathtaking contrast to the deep blackness of night. It's a scene rife with photographic possibilities, and that's where astrophotography comes in.
Astrophotography is the act of photographing astronomical objects and presents a whole range of technical challenges. One of the first is light pollution, the overspill of light from artificial sources like city street lights. To fully appreciate the night sky and capture images of its beauty, you have to escape those city lights and find the darkest place you can. This means getting out of town and into the countryside. You'll want to wait until well after sunset to avoid residual sunlight that lingers in the sky after the sun has recently set. It's also important to have a solid understanding of your digital camera and image-processing software.
Start by playing with your camera's manual features. Place the camera on a tripod and choose the shutter priority mode or bulb mode. These settings are now included on all but the most basic cameras, and either one will let you control shutter speed with precision. Use a shutter release cable so that you don't touch the camera and blur the image. Using a cable release, you can capture single exposures of multiple seconds or even several hours.
After around 15 seconds, stars appear to move across the sky due to the Earth's rotation [source: Heller]. So, if you leave the shutter open long enough, you'll see star trails. Longer exposures create longer trails, filling your composition with blazing pinwheels of starlight.
To capture truly clear images, you'll have to combat the digital noise that plagues all night photos. One way to do this involves taking multiple shots and then using stacking software to combine the images into one. Such software lets you take shorter, less noisy exposures and combines them into a single, crisp image.
Lenses also affect the quality of your images. A decent wide-angle lens will work nicely for skyscapes. But if you have an SLR (single-lens reflex) camera that lets you use different lenses, you may want to invest in a T-ring, which lets you attach your camera to a telescope. This setup allows you to get up close and personal, photographically speaking, with specific stars and planets.
Astrophotography, like all night photography, can be time-consuming and requires patience and experimentation on your part. But no matter which subjects you decide to shoot once darkness shrouds the land, just remember that your imagination (and your camera) can picture what your eyes cannot. With just a flicker of light and some ingenuity, you can become an expert at nighttime photography.