Today I am going to discuss a few simple tips that will allow you to take pictures of the night sky. These may not compare with professional images, but they will be YOUR images!
Because the Earth rotates, the stars appear to move when taking long exposures from a fixed tripod, resulting in ‘star trails.’ The challenge is to take a short enough exposure that the stars appear pin-point, but long enough that faint objects appear in your picture.
To get started, you need only three things… a camera that can take exposures at least 20 seconds long, a wide-angle lens, and a steady place to set the camera. While a tripod is best, a beanbag or a plastic baggy filled with sand or rice will suffice.
While possible to do night photography with a point & shoot camera, the added techniques required prevent discussion here. These tips assume that you have a digital single lens reflex camera (or DSLR) with either a single focal length lens of 15-30 mm or a zoom lens that includes 15-30 mm.
Place the camera on the tripod or beanbag and point it in the direction of the sky in which you are interested. Set the ISO value at 3200 and the exposure to 10 seconds. Use F/4 or faster, although you should avoid the fastest setting for the lens.
Turn off auto-focus. Manually focus on a bright star or planet, using live-view, if available, at highest magnification.
Set the delay on the camera to 2 seconds and press the shutter button. Review your image and re-position the camera to achieve the desired composition.
Once you have reasonable images, download them to your computer and use the software that accompanied your camera and adjust the brightness and contrast to improve the image.
As with any rules of thumb, this is just a starting point. Experiment with exposures up to 30 seconds and ISO values to find the optimum setting for your setup. This is really part of the fun!
Western Slope Skies is produced by members of the Black Canyon Astronomical Society. This episode was written & recorded by Bryan Cashion.