Just Google the subject of orbs, and you’ll be presented with pages of sites discussing the topic, both pro and con. Now everyone seems to have an example to share on the internet. Ghost hunting enthusiasts around the world label these "orbs" and claim they come from a paranormal source.
Ever since George Eastman invented celluloid film for portable cameras in the 1880’s, people have been trying to capture evidence of the paranormal on film, but it wasn’t until the pocket camera with the built-in flash hit the market in 1960 that orbs in photos were noticed.
In the early 1990s, ghost hunters and other paranormal investigators found they were able to take multiple photos at each investigation. Around this time, orbs started to be defined as more than an unexplained spot. Many of these teams wanted to prove that something paranormal was occurring at these sites. So they started to tout these anomalies were actually "ectos" or spirits made visible in their photos. While the public continues to accept orbs as evidence of paranormal activity, most experienced investigators now know what causes most of these anomalies.
Orbs usually appear in digital still photography when a flash is used—they are rare in daylight or with film photography. Occasionally they have been observed moving in video footage. While most orbs appear spherical, other shapes have been reported such as diamonds, rectangles and smears.
One explanation is that these early orbs were just "noise" introduced into the photo by inferior digital imaging chips, especially in low-light conditions. The combination of low light and inferior chips cause situations where the camera won’t be able to fill in all the pixels, resulting in light-colored spots.
Paranormal investigators have tried to duplicate these anomalies. What they found was that the orbs were actually refractions of light from the flash which were reflected back into the camera lens. The usual causes were dust, pollen, moisture, insects, snow and/or rain, or any other small particles.
In a response to a customer’s inquiry, Fuji Films® wrote:
"Floating dust particles may cause white spots appearing at different positions on pictures taken by a digital camera using the flash. Dust in front of a subject reflects the flash light and the image of the dust is captured out of focus. Dust, snow, rain, pollen, condensation, or any small airborne particles may cause the same problem. The particle will appear light and big because it is out of focus; it may assume a shape similar to the aperture of the camera, usually round."
Are there some photos which defy explanation? Yes, there are. However, they are very rare. So if you get a photo with an “orb” in it, just stay still for a moment and take another photo. In other words, just “let the dust settle.”