Long exposure photography is one of the most useful but also most misunderstood approaches in paranormal investigation. Any time you take a photograph in low light, your camera will naturally keep its shutter open for longer. This allows more light to reach the sensor, giving you a brighter image, but it also increases the risk of blur, streaks and ghost-like shapes. Because of this, long exposures have played a huge part in both genuine investigation work and misleading spirit photographs throughout history.

Every camera, whether it's a DSLR, compact, or smartphone, works by exposing its sensor to light for a controlled amount of time. In bright daylight that window might be as short as 1/2000th of a second. In darkness it may stretch to half a second, a full second, or even more.

A "long exposure" simply means that the shutter is open for noticeably longer than normal. Anything that moves while...