The Math Showing That Orbs Are Not Dust, Pollen, or Water Vapor

Orbs are strange-looking circular objects that show up in photos, without any obvious explanation. There are skeptics out there who claim that most of the orbs in photos are just dust. These skeptics all have one thing in common: they forgot to do their math before making such a claim. Let's do the math, which will show that the “orbs are dust” claim is nonsense. Similar math will debunk the idea that pollen or water vapor can explain orbs.

The Math Relating to Dust and Orbs

To do this math, we must consider a simple ratio that I will call the blockage fraction. The blockage fraction is the ratio between the width of a natural particle floating in the air, and the width of the area right in front of a camera lens. Computing such a ratio will tell us whether it is reasonable to think that suspended dust particles in normal air might be big enough to appear as visible orbs in photographs.

For a point-and-click camera, a simple measurement is enough to show the width of the area right in front of the camera lens. This width is roughly 15 millimeters.

But what about the width of natural particles suspended in the air? Although a skeptic may try to “cloud the waters” here by suggesting this is a matter of great uncertainty, it is no such thing. The size of particles floating in the air is settled science widely used by air quality experts, pollution experts, and meteorologists. Scientists have electronic instruments that allow them to measure such particle widths very exactly. Do a Google search for “particle size chart” and you will get quite a few charts that all give pretty much the same numbers (such as those shown in this wikipedia.org article on particulates).

There is general agreement about the following particle size estimates, although estimates may vary by as much as 50%. A micron is a thousandth of a millimeter, or a millionth of a meter. You can find many charts like the one below by doing a Google image search for "particle size chart."

Condition of air	Particle size
Outdoor air, dry	1 micron
Indoors, normal	10 microns
Indoor dust spikes (vacuuming, etc.)	50 microns
Outdoor heavy smog	30 microns
Heavy fog, mist	500 microns
Heavy visible dust in air, reducing visibility	500 microns
Rain	1000 microns or more

Now let's plug these numbers into a spreadsheet that computes the blockage fractions. The spreadsheet is below. The numbers in the fourth column are simply the numbers in the second column divided by the numbers in the third column.

Air Condition	Particle size (microns)	Length of area right in front of lens (microns)	Blockage fraction (maximum size of natural orb as fraction of original photo width)	Would you notice a photo orb caused by a natural particle suspended in air?
Outdoor air, dry	1	15000	0.00007 or 1/15000	No
Indoors, normal	10	15000	0.00067 or 1/1500	No
Indoor, dust spikes (vacuuming, etc.)	50	15000	0.0033 or 1/300	No
Outdoor heavy smog	30	15000	0.002 or 1/500	No
Thick fog or mist	500	15000	0.03 or 1/30	Maybe
Heavy visible dust in air, reducing visibility	500	15000	0.03 or 1/30	Maybe
Rain	1000 or more	15000	0.07 or more	Maybe

This table tells us how absurd is the notion that dust particles in ordinary outdoor air are sufficient to produce orbs in photographs. Since such particles cannot block more than about 1/15000 (one fifteen thousandth) of the original photo width, they are many times too small to produce noticeable orbs in photos. This table also tells us that dust particles in ordinary indoor air are way too small to produce orbs in photos. Such particles cannot block more than about 1/1500 (one fifteen hundredth) of the original photo width.

You also need not suspect that some orb in an indoor photo was caused by some dust spike causing the average particle size to rise as high as 500 microns – not unless the visibility was sharply reduced, and the air was visibly thick with dust. Whenever the air becomes filled with particle sizes larger than 100 microns, they decrease visibility quite noticeably, because the human eye can detect particles as large as 50 microns. So unless you were blasting out a wall during construction or toppling a large book case or making a big mess in the kitchen with lots of baking powder flying around – or doing something else that caused a noticeable decrease in visibility – there is no chance that the natural particles in the air were sufficient to produce noticeable orbs in a photo. Particles as large as 100 microns or larger always settle to the ground fairly quickly, at a rate of about a meter per six minutes. So indoor dust spikes quickly die out.

Could it be that we might get a different “blockage fraction” when we consider not a point-and-shoot camera but an expensive DSLR camera with a much wider lens? Yes, but in this case the “blockage fraction” would not be larger, but 50% smaller. So things aren't helped if a skeptic assumes a big camera lens was used – in fact, it then becomes twice as hard to believe that natural particles may have caused an orb.

In this discussion I have been extremely generous to the skeptic, by assuming pretty much the smallest possible “length of area right in front of lens” (the second column in the spreadsheet above). In fact, any particle photographed right next to the camera lens will appear as very blurred. When considering an orb that appears with a sharp, non-blurred edge, you must consider a “length of area right in front of lens” to be 2 or 3 times larger than 15 millimeters. That results in a “blockage fraction” that is even smaller (by a factor of two or three times) than the fractions shown above, which just makes it two or three times more unlikely than orbs in ordinary air could be produced by natural particles.

These considerations clearly show that dust cannot be a major source of orbs in photos. Under 99% of the conditions under which orb photos are taken, the particles of dust in the air are way, way too small to produce orbs that you might notice in a photo.

The Math Relating to Pollen and Orbs

Now let's consider the math relating to pollen and orbs. We must again consider particle sizes. Almost all types of pollen have particle sizes less than 50 microns, although a few types of pollen have particle sizes as large as 100 microns. So you might think that if we use a chart like the one above, we would consider that a pollen particle might block as much as 1/150^th of a photo width.

But there is another important thing to consider in regard to pollen: the number of particles per cubic meter. A pollen forecast is normally given as low, medium, high, or very high (and it is very rare to get the “very high” forecast). Here are the number of pollen particles per cubic meter that correspond to these forecasts, according to a page from the University of Worcester (similar information is given here).

Pollen Forecast	Pollen Particles Per Cubic Meter
Low	Less than 30
Medium	30 to 49
High	50 to 149
Very high	150 or more

Now, from these figures we can calculate a likelihood of a pollen particle existing in the area right in front of the camera. Since pollen particles are so small ( less than 100 microns), we can conclude that if a pollen particle was not right in front of the camera, it could not possibly appear as an orb in a photo. The area right in front of a point-and-click camera has a width of about 15 millimeters (15,000 microns), which is equal to 1.5 centimeters. What fraction of a cubic meter is a cubic area with a width of 1.5 centimeters? It is only 1 divided by 666,666. Even if we assume that a pollen particle might be visible in a photo if it appeared in a slightly larger volume next to the camera lens (an area of 4 cubic centimeters), that 4 cubic centimeters is only 1/250,000 (one two hundred fifty thousandth) of a cubic meter.

Using that figure, we can expand the table above to show what the probability would be of a pollen particle being right next to your camera lens when you take a flash photo. The fourth column is obtained simply by dividing the second column by the third column.

Pollen forecast	Pollen particles per cubic meter	Number of 4 cubic centimeter volumes per cubic meter	Chance of a pollen particle existing in a 4 cubic centimeter volume right next to camera lens
Low	Less than 30	250000	Less than 1 in 8333
Medium	30 to 49	250000	Between 1 in 8333 and 1 in 5102
High	50 to 149	250000	Between 1 in 5000 and 1 in 1678
Very high	150 or more	250000	Greater than 1 in 1678

Given that the “very high” pollen forecast is very rare, what these probabilities means is that your chance of taking an outdoor photo and having a pollen particle floating right next to your camera lens when you take a flash photo is negligible. Perhaps a few times in a lifetime, a photographer might take a flash photo in which a speck-like orb showed up because a pollen particle was floating right next to the camera lens. But given the probabilities above, we should not expect that to happen more than once in a year. So pollen can be ruled out as a source of orbs in photos, except for the most extremely rare “blue moon” type of event, which would only result in something like a speck on a photo. We can therefore be quite confident that 99% of the orbs shown in photos were not caused by pollen particles. I also have many photos (shown here) that show lots of orbs on days when the local pollen count listed on pollen.com was very low.

Mold Spores

Mold spores are more common than pollen particles, but mold spores are much smaller, being smaller than about 50 microns in width.  This means the math for a mold spore is similar to the "vacuuming" case discussed above. So mold spores can't block more than about 1/300 of the width of the photo, which is too small to produce anything more than a speck in a photo.
 

Water vapor particles

Another possibility sometimes mentioned as a natural source of orbs is water vapor particles in the air. But water vapor particles in ordinary air (called aerosols) are not any larger than dust. So the same blockage fraction consideration (discussed above) that rules out dust in ordinary air as a source of orbs also rules out water vapor or aerosols in ordinary air as a source of orbs. Since water vapor in ordinary air only has a particle size on the order of 1 micron or less, a typical particle of water vapor will  block no more than 1/15000 (one fifteen thousandth) of the area in front of a point-and-click camera (15 millimeters or 15,000 microns), which is way too little to produce an orb in a photo.

The only exception is the case of heavy fog or heavy mist, which is quite rare and very easy to notice. Heavy fog or mist can account naturally for no more than a tiny fraction of orbs photos (because of the rareness of heavy fog or mist in almost all locales). Heavy fog or mist cannot account for any of the paranormal-looking orb photos on this site, as I am careful not to photograph under conditions of fog or mist (which is very rare where I live during the hours that I photograph).

In the very rare cases in which heavy fog or mist occurs in the air, in sufficient amounts to produce orbs, it blankets most of the photo with little circles, making it very easy to notice, and making it unsuitable for an explanation of any photos showing one or a few orbs in a photo.

Conclusion

The bottom line is: virtually all orbs produced in photos taken in normal indoor conditions and dry outdoor conditions cannot be the result of any natural particles in the air, for the particles floating about in the air under such conditions are way too small to produce orbs in photos (or, in the case of pollen, both too small to produce orbs bigger than specks, and also exceedingly unlikely to appear right in front of the camera lens). So why is it, then, that the “orbs are dust” idea has been so widely spread about? The reason is that skeptics have an extremely effective propaganda machine which allows them to spread their ideas far and wide – even when they are in glaring conflict with well-established facts such as the average sizes of particles in the air.

These conclusions are confirmed by the simple observational fact that at least 99% of the total number of flash photos taken by the world's photographers do not show orbs. If dust or pollen or water vapor in ordinary air was sufficient to produce orbs, then a large fraction of the world's flash photographs would show orbs -- but much less than 1% of such photos show orbs.  The skeptic conveniently ignores this fact, which by itself is sufficient to rule out the hypothesis that most orbs in photos are caused by dust, water vapor, or pollen. 

Are there any known natural or artificial things that can cause orbs in photos? Yes, those things are heavy fog or heavy mist, rain, and lens flare. I am sure that the great majority of photos on this web site cannot be explained by assuming that any of these things was the cause. I know that rain, fog, or mist cannot explain orbs in any significant fraction of my outdoor photos because I am careful to avoid taking photos when any of these things are present (and when presenting an outdoor photo I always state that none of these things were present). I also know that lens flare (which almost always has a very distinctive “easy-to-spot” look) is not a cause for any large fraction of my orb photos, because lens flare is only produced when you point the camera at the sun or a very bright artificial light close to the camera (something I am very careful to avoid). All of my many Grand Central Station are photos taken from balcony spots in which there is never a bright light near the camera.

In short, the orb photos on this site are mysteries that cannot be currently explained. Maybe someday someone might think of some ingenuous natural explanation, but none of the things discussed here are suitable candidates.

Below is an example of a photo completely inexplicable through any hypothesis of natural particles in front of the camera. The photo was taken on a dry cloudless night (November 10, 2017) with no fog, mist, rain, or precipitation, a night on which the moon was only a half moon. We see a very bright moving orb that is 11 percent of the original photo height.  To produce such an orb, a dust particle would have to have a width of about 1500 microns -- some 1500 times greater than the actual width of particles on a day like this. In fact, dust particles suspended in the air never get larger than a width of about 1000 microns, even when the dust is so heavy that it blocks visibility. See here for 86 similar photos showing large orbs.

 See my posts labeled "air orb too large to be dust" for 86 similar photos, including some showing orbs larger than 60% of the photo height.

The overall reasons for rejecting the idea that orbs are particles of dust near the camera include the facts that many orbs are too big to be dust (for the reasons discussed in this post), too bright to be dust (as shown in my 500+ posts labeled "bright air orb"), too fast-moving to be dust (as shown in my 500+ posts labeled "speeding air orb"),  too colorful to be dust (as shown in my 1500+ posts labeled either "blue air orb," "yellow air orb," "purple air orb," "green air orb," "pink air orb," or "orange air orb"), or too far from the camera to be dust (as shown in my 66 posts labeled "air orb too distant to be dust" which often show orbs partially behind distant obstructions).

Further very strong evidence against the idea that orbs are dust is the fact that when I start getting lots of orbs in my photos, I often pull out a piece of cardboard, and photograph it at arm's length; but not once have any of the resulting photos shown a single orb in front of the piece of cardboard. You can see these photos by looking at my 41 posts labeled "cardboard test." 

Further  very strong evidence against the idea that orbs are dust is the fact that I very often have seen a very strong "vertical bias" in my orb photos -- a tendency for orbs to appear many times more frequently in the upper part of my photos. See my posts labeled "orb vertical bias" for examples.  Such photos are completely inconsistent with the idea that the orbs are being caused by natural particles near the camera, for such particles would appear randomly across the photo area, not many times more often in the upper part of the photo.  For example, in this series of photos I found there were about 845 orbs that were not in front of a building at the bottom of the photos, and only about 7 orbs that were in front of that building.  This extremely strong "vertical bias" is completely inconsistent with any explanation that the orbs were being caused by natural particles (such as dust) very near the camera. 

 Further  very strong evidence against the idea that orbs are dust is the fact that when you attempt to photograph dust in front of the camera (using artificial techniques such as squeezing a dusty cloth right in front of the camera), such as shown here, the resulting dust orbs are dull, colorless, featureless, small, and with blurry edges. Contrast these with the orbs shown on this site, which are so often colorful, bright, and with sharp edges and face-like details or stripes or  outer rings. 

The diagram below may help to illustrate how absurd it is to try to explain photos like the one above as photos of dust.  The diagram shows one tenth of the area right in front of a point-and-click camera lens with a diameter of about 15 millimeters (15,000 microns).  The arrow points to a tiny particle that is the size of the largest dust particles floating about in ordinary indoor air (which are only about 10 microns).  The particle is so small you won't be able to see it clearly unless you bring up the image in an editor and zoom in.  Could a particle this size cause an orb as big as the one shown above? No, it's many times too small.  For me to have got a picture like the one above from a floating dust particle would have required a dust particle of some 1500 microns. Dust particles in ordinary outdoor air are only about 1 micron, and if they are ever bigger than 50 microns visibility is sharply reduced.  

 Postscript: For a discussion of the type of misleading videos and photos produced by skeptics trying to suggest that orbs are dust (which typically involve raising dust levels much higher than normal), see this post entitled, "When Skeptics Engage in Deceptive Cheating." 

An explanation sometimes given for mysterious orbs is that they are particles of dust on a camera lens. A small particle resting on a camera lens will absolutely not produce something that looks like an orb in a photo. You can prove that by doing this experiment:
(1) point your camera at the ceiling, with the lens open;
(2) place a tiny particle like a bread crumb on your lens;
(3) take a photo;
(4) blow the particle off of your camera lens.

You will see that the photo absolutely does not show anything that looks like an orb.  

Postscript: The images below show orbs I have photographed with the same strange squiggly pattern (as reported here). The probability of coincidentally getting this much pattern repetition from natural particles is zero. 

 Below is another example of a recurring orb pattern, as reported here.  We see six repetitions of an inverted Y pattern, a degree of repetition that would be impossible if natural particles were being observed. 

See here for more than 25 other other examples of recurring patterns in mysterious orbs, with such a huge number of pattern repetitions that there is no chance that natural particles could have produced  them. 

As you can see in this series of posts, I have photographed more than 700 cases of mysterious orbs with stripes (most of which can seen in this video).  Each of these is a case of a clear sharp detail appearing in an orb. No such photos can be explained as out-of-focus dust particles near the camera, for we would see no clear, sharp details in an out-of-focus particle near the camera.  It is futile to claim that such striped orbs are "striped dust." My photos of 700 mysterious orbs with stripes were published prior to September 5, 2019. But doing a Google search for the exact phrase "striped dust," I see that no has used that phrase before September 5, 2019 in connection with any claim that dust particles can have stripes.