Orbs are small spheres of glowing light that appear in photographs and videos, usually when the image is captured at night, especially when using an infrared night vision camera or flash.
At one time the most common theory within the paranormal community was that orbs spotted in photos and videos captured at allegedly haunted locations are evidence of the existence of the paranormal. They are said to be the early stages of a spirit or ghost manifesting, although I don't recall hearing any stories of these orb sighting evolving into a full apparition.
This phenomenon really dates back to an earlier, less scientific era of ghost hunting and paranormal investigation, and was spurred on by the introduction of the first consumer camcorders to include night vision capability, which became widely available by the early 2000s.
While most aspects of the paranormal, such as the use of Ouija boards, EMF meters and cold spots are regarded to be paranormally proven, orbs are debated and split the paranormal world. Today many paranormal investigators simply put orbs down to a camera anomaly rather than paranormal evidence.
Those who believe say the orbs are a manifestation of an unknown energy and are said to emit their own light. Orbs have been captured which appear to be many different colours, although they are most commonly often pure white or transparent. They either appear on their own, or in groups, clustered together.
Sometimes, people even claim to be able to see human faces in the orbs, although this is simply an example of pareidolia, our subconscious tendency to turn random patterns into identifiable objects, such as 'the man on the moon'.
Paranormal investigators have even categorised the different colours, for example it's thought that white orbs are a positive energy, while red suggests a protective spirit is present, and black signals the presence of a negative or angry entity. As these orbs are said to be the result of an energy that we don't yet understand, quite how investigators had jumped to a conclusion about these differing colours is unclear.
A growing percentage of the paranormal community is coming to terms with the fact that orbs can be explained as being normal, rather than paranormal, and it's thanks to the overwhelming amount of evidence that has been offered up to debunk the paranormal claims.
Everyone from amateur ghost hunters, to members of the public, camera manufactures and even scientists have had their say on the phenomenon.
In reality, orbs are a result of several proven things, including drops of moisture on a camera lens and light refracting in the camera's lens which causes a light anomaly known as a lens flare. Light reflecting off of nearby surfaces, either inside or out of the cameras field of view is also a cause, as is light reflecting off of tiny particles in the air.
Particles in the air are the most common cause, this can be anything from dust, water vapour, rain, snow, or even insects. They are most visible when the camera is using a flash or spot light, or it is in night vision mode. They can also be visible in a photograph when the particles pass through a strong beam of light, like a beam of sunshine through a window.
Fujifilm recognise orbs as a common photographic problem and say that "there is always a certain amount of dust floating around in the air. You may have noticed this at the movies when you look up at the light coming from the movie projector and notice the bright sparks floating around in the beam. In the same way, there are always dust particles floating around nearby when you take pictures with your camera. When you use the flash, the light from the flash reflects off the dust particles and is sometimes captured in your shot."
Fuji add that the reason tiny specks of dust can be so visible on camera is down to its proximity to the camera and the nature of how the camera focuses, "dust particles very close to the camera are blurred since they are not in focus, but because they reflect the light more strongly than the more distant main subject of the shot, that reflected light can sometimes be captured by the camera and recorded on the resulting image as round white spots. So these dots are the blurred images of dust particles."
The effect is also seen on night vision video cameras, where bright infrared LEDs illuminate microscopic particles very close to the lens. The artefacts are especially common with compact cameras, where the short distance between the lens and the built-in flash decreases the angle of light reflection to the lens, directly illuminating the aspect of the particles facing the lens and increasing the camera's ability to capture the light reflected off normally sub-visible particles.
It's for this reason that more and more people are capturing orbs in photos, cameras are getting more compact and the flash is getting closer and closer to the lens. Smartphone cameras tend to have a tiny flash right next to the tiny lens, the two couldn't be any closer.
Although largely debunked, some believers are clinging on to the idea of orbs by admitting that some orbs are the result of dust or light, but say that some are genuinely paranormal. They say they can tell the difference by looking for spokes of light, which they say show that it is caused by some kind of light anomaly, where as solid orbs are said to be the real deal.
Like it or not, the truth is, there is no evidence at all that orbs are a paranormal phenomenon. The claims that they are are nothing more than a belief or theory based on observations by paranormal researchers. However, there is plenty of evidence which confirms that some, if not all, orbs are dust, lens flares and other artefacts.
Having said that, it's still always a bit of a thrill when you spot an eerie ball of light moving across the screen in a video taken a haunted location on a ghost hunt.