…continuedPhotographing the Aurora
Shooting Auroras with a Digital Camera
The age of the digital camera is here. As prices fall, new models appear, and features improve, these cameras are dramatically changing the way amateur astronomers "photograph" the sky. So does that mean a digital camera can be used to capture images of the aurora? Absolutely, though there are some caveats.
Older cameras, particularly the early point-and-shoot models, may not be useful for aurora photography. But before you start looking either for an old manual camera or a new digital wonder, check to see if your current camera can be set to an ISO of at least 100. Higher is better (up to ISO 400 or even 800) but as the image above shows, if the aurora is bright enough, a low ISO will suffice.
If your digital camera can do all these things, then you're ready to shoot an aurora the next time one appears.
Most suggestions for auroral photography apply whether your camera is digital or uses film. These include using a fast (at least f/2.8), wide-angle lens, fast film (or a high ISO setting on a digital camera), a sturdy tripod, and a cable release (if your camera can take one). And don't forget to bracket your exposures that is, shoot a variety of exposures that can range from 5 to 60 seconds in length.
Some comments, though, are applicable only to the digital domain. For example, when the camera operates in time-exposure mode, noise in the form of bright, randomly spaced pixels can appear in the image. The longer the exposure, the more apparent the noise. (Of course, if the aurora is bright enough, you won’t see the noise!) Most new digital cameras have noise-reduction settings that automatically come into play during time exposures. But be warned: there's a catch. Once the exposure is finished, the camera generates a "black" image that enables it to eliminate the noise in the original image. That "black" image takes just as long to generate as the length of time of your original exposure. So if you take a 60-second shot of the aurora, you'll have to wait another 60 seconds for the camera to "do its thing" before you can shoot again.
Something else to keep in mind is that digital cameras can get warm. A hot camera generates noise, so turn the camera off if you're not using it. Also, turn off any features you don't need, including the flash. And don't be afraid to fill up the memory card (the camera’s image-storage media). The delete button is your friend for getting rid of unwanted images. In fact, the best thing about using a digital camera is that you can see the results immediately, know whether you're getting good images or not, and make adjustments accordingly.