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A Scientific Case Study: The Orb Zone Theory

It can sometimes be difficult for those without relevant training to appreciate how science works. Science works differently to everyday life. In the world of science, for instance, it is evidence that counts over everything else, including personal opinion. To better appreciate just how the scientific process works, here is a case study to consider. It concerns orbs, which are thought by many to be paranormal.

In essence, the scientific process goes as follows. Someone makes novel observation of a phenomenon and formulates a theory to explain it. They produce predictions from that theory and test them with experiments or more observations. If the new theory proves to be correct, then it might replace existing theories. There are two conditions that determine if this happens, though: (a) the new theory must explain everything the old theory did, as well as the new observations, (b) the new evidence must be beyond reasonable doubt and any experiments must be rigorous. In addition, scientific theories should fit in with existing science in related areas of science. If you invent a new agency to explain orbs, for instance, this might contradict evidence from other areas of science. Bearing in mind that these other areas of scientific knowledge are supported by their own hard-won evidence, you would need to demonstrate that they were wrong too before your theory could be accepted. Most paranormal theories do not achieve these conditions.

The Orb Zone Theory explains why cameras record orbs. Serious photographers recognised these 'orbs' straight away as 'circles of confusion' (a technical term in photography). They were bemused by the enormous interest orbs attracted among paranormal researchers. Knowing the orbs' origins, they felt no need to explain them in any detail. As a result, it was left to paranormal researchers themselves to expand on the simple idea of 'circles of confusion' to explain the various aspects of the orb phenomenon in detail. This was how the Orb Zone Theory appeared.


Orbs were first noticed in the early digital photographs. These grey or white circles, sometimes opaque but usually translucent, were never seen when the photo was taken. For this reason some people thought they were paranormal. It was quickly realised, however, that they could be easily reproduced by blowing dust (or similar small particles) just in front of the lens when flash photographs are taken. Many paranormal researchers left it at that, assuming that all orbs were caused by dust. Others were not so sure as variations on the classic orb theme, like coloured or oddly shaped versions, began to appear. Then photos appeared that seemed to show orbs behind other objects in the picture. Some people claimed that orbs only appeared in particular places, such as haunted houses, or around particular people. It was clear that a more detailed answer to the orb question, beyond simply saying 'they're all dust', was required. The Orb Zone Theory was created to fill that gap.

Orb Zone primer

The Orb Zone Theory (OZT) is essentially an extension of the 'circle of confusion' explanation for orbs given by camera Orbingmanufacturers and serious photographers. In essence, an orb is a circle of confusion which is an out of focus highlight. If you look at a photograph with out of focus objects, like the one on the right, you will see that instead of just going fuzzy, objects going out of focus turn into many overlapping circles of light (circles of confusion). Do they look familiar?

Obviously, the brightest circles of confusion, produced by highlights on the objects in the photo, outshine the darker ones completely. If you look at any shiny object you will see that, no matter what the colour of the object, the highlights are always white (or the colour of the light source). As orbs reflect the light from a white light flash, that is why most are white (or grey if more diffuse).

So, what is a circle of confusion? It is the smallest detail that a lens can resolve. When it is projected onto a film or sensor chip it appears as a tiny circular dot. These dots are deliberately made small enough so that people cannot see them as individual dots. Instead the picture appears as continuous shapes, rather than thousands of dots. It is a bit like the way a TV picture is made up of many lines that you can see if you look closely enough. Note, however, that circles of confusion are not the same as pixels!

When an object in a photo is out of focus, its circles of confusion expand to appear as circles (see diagram and photo above). The larger the circle, the fainter it is, because the light is more spread out. Eventually, when the circle becomes too large, it is no longer visible at all. This places a limit on the largest 'orb' you can see in a photo. This is why you never see orbs over about one tenth of a frame size*. If orbs were real objects 'out there', you would not expect them to have such a limit on their size in a photo.

A crucial question is - why did orbs suddenly appear when digital cameras arrived? The sensor chips in digital cameras are almost all physically smaller than the size of a 35mm film frame (most are less than half the size). This meant that wider-angle lenses were needed for digital cameras so they could show the same area of view in a frame as a 35mm film cameras (otherwise digital cameras would have shown a much smaller area of view). These wider-angled lenses had a much greater depth of field. Depth of field is the area in front of a camera where objects are in focus. If objects are too close to the lens (and sometimes when they are too far away) they will be out of focus and break up into circles of confusion (see pic above). The increased depth of field in digital cameras meant that the closest distance where objects were in focus came much nearer to the camera. It also brought the area that was just out of focus much closer. Importantly, it brought these two zones much closer to the flash unit. In many digital cameras this created an Orb Zone. The orb zone is the area where the flash is strong enough to illuminate tiny particles, like dust, water droplets or small insects, that are just too close to the camera to be in focus. Such objects produce expanded circles of confusion or orbs! Since most bits of dust are tiny, they only have a single highlight and so produce individual orbs. Some larger objects, like small insects, may have several highlights and so produce multiple overlapping orbs.

Though the vast majority of orbs are circular, they can be other shapes. Though the basic shape is derived from the circle of confusion, it can be modified by the diaphragm in a camera lens. This diaphragm is an adjustable opening inside the lens ('the aperture') which varies in size to let more or less light in (note that this has nothing to do with the camera shutter). Though it is usually circular, it can be other shapes, notably a diamond or hexagon. Cameras that produce diamond shaped orbs (or other odd shapes) will always produce them in this shape because of their diaphragm. Since the diaphragm varies to control how much light is admitted to the camera, the diamond (or other shape) shape may be more pronounced in some photos than in others (depending on the size of the aperture) and may even vanish completely in some shots. Orb shapes can also be modified by vignetting, as explained below, and by overlapping with other orbs.

Various factors affect the brightness, structure (internal shapes, such as concentric circles, if any), edge sharpness and evenness of shading. These are mostly down to the camera lens. Photographers talk about the bokeh of a lens when discussing this subject.

*Lens flare, which resembles orbs, can be bigger than one tenth of the frame size. Lens flare is associated with bright light sources either in the frame or just outside it. It is usually quite easy to recognise.

Has the Orb Zone Theory been tested?

For a scientific theory to be validated, it needs to produce predictions and these need to be tested. Ideally, these predictions should be of things not already observed. If a theory only 'explains' existing observations, but cannot predict any others, it could be no more than speculation. Several predictions of the Orb Zone Theory have been formally tested to scientific standards. These include:

  • that orb numbers vary according to the depth of field in a particular photo
  • that orb numbers are unaffected by the megapixels of a camera
  • that orb numbers are unaffected by whether photos are taken in haunted or non-haunted locations

In each of these tests, everything was done to hold other variables (that were likely to affect the outcome) constant. It was then possible to see if there was any statistically significant relationship either supporting or refuting the predictions.

The first test concerned the central basis of the theory - that it is the distance of the closest point at which objects are in focus is what determines how many orbs will be seen. Such a relationship is unlikely to be predicted in paranormal theories of orbs which aren't usually concerned with the mechanics of taking photos. The second test concerned an idea proposed by some people that higher megapixel cameras produce fewer orbs*. The third test concerned the widely-held idea that haunted places produce more orbs. Some people propose, for instance, that orbs are actually ghosts or are the precursors of ghostly manifestations.

When these predictions were tested in rigorous conditions, they were all confirmed.

In addition, the OZT has explained many 'odd' kinds of orbs that were seen by some as 'beyond the dust theory', and so possibly paranormal (see the next section). The OZT has successfully explained many types of orb from hundreds of photos taken with dozens of different camera models in many different places and in all sorts of different conditions. These unusual orbs have also been successfully reproduced using the principles of the OZT.

Another interesting test that ASSAP once proposed was Project Orbit. The idea was to see if two cameras could record the same orb. OZT predicts that because the zones are so close to the camera lens, the same orb will NOT appear in both shots, showing it is a bit of dust or other particle very close to the lens. For various reasons Orbit never happened but paranormal research group Parascience has done similar tests and confirmed what the OZT predicted. See here for details.

* Though the number of megapixels is irrelevant in the Orb Zone theory, the physical size of the sensor chip is not. More recent cameras tend to have larger sensors as well as more megapixels. This means their lenses have a smaller depth of field which reduces the likelihood of orbs.

What does the Orb Zone Theory explain?

When scientists discover a general principle or theory, they usually assume it applies to all known examples of the phenomena. For instance, when Newton discovered gravity he assumed it applied to all objects. He didn't think that, though gravity held Mercury and Venus in their orbits around the Sun, something else kept Jupiter in its orbit!

So, if dust causes most orbs, it is logical to infer that it causes all orbs. However, some paranormal researchers have said that certain orbs are so different that they must have a different explanation. There is a problem with this argument, however. Orbs only appeared widely with the arrival of digital cameras. Why should digital cameras just happen to be good at detecting both dust orbs and the proposed paranormal orbs? Some people have said it is because digital cameras are more sensitive to infra-red than film cameras but this is not true. Though their sensors are indeed highly sensitive to near infra-red, digital cameras are fitted with permanent internal filters to block most infra-red. Overall, they are no more sensitive to infra-red than were film cameras.

With the OZT, it has been possible to explain all aspects of the orb photographs so far examined in detail, including some oddities. Here are a few examples of things explained by OZT:

  • that the vast majority are white or shades of grey (because highlights are the same colour as the light source as explained above)**
  • that orbs sometimes appear truncated around the edges of frames in some photos (caused by vignetting as the dust is very close to the lens)
  • how orbs can appear in front of backgrounds too close to be in focus (because they are very close and out of focus themselves, not in focus objects 'out there')
  • how orbs can appear to be moving (they are multiple overlapping orbs caused by objects with several highlights, like insects)*
  • how orbs can have tails, usually fading away downwards (because they are falling raindrops)
  • why orbs are never larger than around one tenth of the size of the photo frame (see above)
  • why cameras that produce odd-shaped orbs, such as diamonds, always get the same shape in all orbs

* Some people claim to have tracked individual orbs moving between photos taken in rapid succession and so have concluded that they are moving very quickly. One obvious difficulty here is, how do they know it is the same orb in both photos? Most orbs are featureless amorphous grey or white circles. Even if one could prove that the sane orb appears in two successive photos, it doesn't mean they are moving fast. The orb could indeed be caused by exactly the same bit of dust. However, it only needs to move a very short distance slowly in the orb zone, which is very small and close to the camera, to appear to move a long way in the photo.
** Some orbs do have colours other that white or grey. However, these can be explained by Moire fringes, refraction in water droplets and chromatic aberration, none of which contradict the OZT.

What cannot be explained?

A theory cannot be considered scientific unless it is falsifiable. This means, there must be some evidence that could appear, or an experiment that can be done, that would prove the theory wrong. If a theory cannot be falsified then it explains everything and therefore, effectively, nothing.

Consider the following possibilities that might falsify the Orb Zone Theory:

a) Supposing there was a photo showing an orb partly behind an object in the picture. This could not be explained by the OZT where orbs are caused by objects just in front of the camera lens. Such photos do exist. However, in all the examples so far examined, the faint translucent orb was overwhelmed by a highly saturated colour in the object supposedly obscuring it. In other words, the missing portion of the orb could not be seen because it was overwhelmed by the more strongly coloured object behind it (particularly if it is highly coloured or very dark or light). Digital photography is more prone to this sort of effect because it has a smaller latitude (degree of detail visible in dark or light areas) than film*. See this page for more information. In fact, it is a legitimate question to ask why, if orbs are really 'out there' (as opposed to being very close to the lens), they always appear to be in front of the many varied subjects of orb photographs (covering a wide range of distance from the camera)? There ought to be lots of photos showing orbs partially obscured by other objects but in fact such pictures are extremely rare. The effect of a partially obscured orb is quite easily reproduced!
* Interestingly, you can sometimes the effect that the colour of the orb has on the object behind (usually making it slightly lighter) even though the shape of the orb cannot itself be made out. If the orb was really behind, it should have no effect on the colour of the object.

b) Another confounding type of photo might be one showing an orb with a shadow. These, too, have been reported and some examined. However, in all cases the 'shadow' was usually either a coincidental dark shape or, more often, the result of over-processing the photo.

c) What if orbs appeared more frequently in haunted locations or around particular people or events? Research has shown no evidence of more orbs in haunted locations than in non-haunted places. However, there have been claims that certain people or places 'attract' orbs or even that some people can 'will' them to appear. To test such claims requires more than just examining photos. All such claims of orbs around particular people or places could just be coincidence. It requires a carefully designed controlled trial, similar to the one that showed that haunted places are no more likely to have orbs than non-haunted places, to test the claim.

d) What if orbs were seen by witnesses at the time they were being photographed? This has been reported, though very rarely. Even if it is demonstrated to be true, it does not affect the OZT. This is because, the OZT does not cover such 'orbs'. Such phenomena should not be considered orbs at all. The OZT is only concerned with 'orbs', which are defined as NOT being seen when the photograph was taken. Lights have been reported in haunting cases for decades, long before the advent of digital cameras, and are nothing to do with orbs despite a superficial similarity. Indeed, the widespread interest in orbs may be affecting such reports.

Is there a better theory?

All scientific theories are only provisional, current only until something better comes along. This usually happens when an observation is reported that can't be explained by the existing theory. However, any new theory must still explain everything that the existing theory does, as well as any new observations.

A rival theory to the OZT would therefore need to explain not only the novel observations but also:

  • why orbs are so much more common on (though not exclusive to) digital cameras than film camera
  • why the vast majority of orbs are white or grey
  • why the number of orbs seen is affected by the depth of field of a camera lens
  • why you can take photos of orbs in front of backgrounds too close to be in focus
  • why some orbs are truncated on the edges of some photos
  • why orbs never exceed about one tenth of the frame size
  • why orbs are always in front of the many varied subjects in orb photos
  • why some cameras always produce odd-shaped orbs (such as diamond shape)

There are lots of other more minor things that would also need to be explained but explaining everything on this list would be a good start to a better theory.

Are there any paranormal orbs?

This question is examined here.

© Maurice Townsend 2007