Auroras are among the most beautiful and awe-inspiring of natural phenomena. Until the late 18th century, observers were frustrated to try to describe in words or sketches what they had seen. Upon its invention photography promised to better capture the phenomenon, but doing so proved difficult. Early black-and-white films required long exposures (5 to 10 minutes), resulting in blurred, low-contrast pictures. The first photographs to convey some sense of the forms of the aurora were taken in 1892 by the German physicist Martin Brendel. The first color pictures were not taken until about 1950, and Life magazine published color aurora photographs in 1953.

Since the 1950s, faster lenses and color emulsions have passed auroral photography from the hands of scientists to enthusiastic amateur and professional photographers. But while a good auroral display is a visually spectacular phenomenon to the dark-adapted human eye, even the fastest modern color emulsions are not so easily impressed. Auroral photographs require time exposures, with the length of exposure depending on the brightness of the aurora, the speed of the lens, and the ISO rating of the film. During the time required to obtain a satisfactory exposure, the aurora will usually undergo some movement and so cause some blurring of the image. Note, too, that as time exposures increase beyond a few seconds the reciprocity effect on color films reduces the gains to be had by increasing exposure time.

The fastest lenses available for modern 35-millimeter cameras are typically f/1.0 to f/1.2; for medium-format cameras the fastest lenses are usually f/2.8 (though Hasselblad makes a 110-mm, f/2.0 lens). Color film at ISO 800 is readily available, and higher speeds are sold, though they often compromise on color reproduction, black rendition (for dark skies), and graininess. The following table recommends exposure times for various auroral brightness levels (see "An Aurora Watcher's Guide" for an explanation of auroral brightness).

Recommended Auroral Exposures (in seconds, with ISO 400 film)
Auroral Brightness   (IBC)	f/1.0	f/1.4	f/2.0	f/2.8
1	10-15	15-25	20-30	40-60
2	2-4	4-8	8-15	20-30
3	0.5-0.1	1-2	2-4	5-10
4	0.1-0.2	0.2-0.5	0.5-1	2-3

Other practical pointers: A firm tripod and a cable release are essential. If the temperature is extremely cold, film should be wound slowly, and rewound with the camera grounded, to prevent static electricity from leaving spark marks on the film.