Particle Size Analysis Refutes the “Orbs Are Dust” Theory

Orbs are circular anomalies that have been observed in many flash photos. You can see very many examples of orbs by looking at this list of web sites or this web site. These are often big, bright, colorful orbs that often appear to resemble faces, and many of these orbs appear to be moving very rapidly (as you can see by looking at this poster-type image). But skeptics often claim that orbs are just dust. They advance the theory that when you take a flash photograph of orbs under some ordinary conditions, you are really just photographing tiny specks of dust in front of the camera.

This theory is wrong, and I can tell you by how much of a factor it is wrong. The theory is wrong by a factor of 1000 times, and is therefore as wrong as the claim that you can buy a shiny brand new car for only 20 dollars. The particles of dust in ordinary air are about 1000 times too small to produce conspicuous orbs in your photographs.

To support this claim, I will present a logarithmic chart of particle sizes. The chart is very similar to many charts that have already been published, except for the yellow and green parts. You can find many similar charts on the Internet by doing a Google image search for “particle size chart.” One such chart can be found here. My chart uses the same estimates found in such charts. There is no real controversy or debate about the particle sizes of the items I have listed here in blue – the great majority of the “particle size” charts list the same estimates I have listed here (although some list “heavy dust” as being no larger than 500 microns). 

 

In this chart I list in yellow a range of particle sizes that might produce a conspicuous natural orb in your photograph because of a camera flash reflecting off of a particle in front of your camera. I define a “conspicuous” natural orb as one that has a size greater than about 3 percent of the original width of the photo. The word “original” here is crucial. By original, I mean the photo before any cropping has been done.

Note that the maximum size of ordinary atmospheric dust is only about 1 micron. But what is the minimum particle size that might produce a conspicuous natural orb in a normal photo, one greater than about 3% of the original photo width ? My experiments tell me that the size is about 1000 microns, or about a millimeter. By a normal photo I mean a photo taken with a normal camera setting as you might use to photograph a person, not some “macro-mode” photo in which the camera lens is extended way out (as you might use to get a closeup photo of a tiny object).

Specifically:

1. I have done tests pouring cinnamon powder near the camera, which produced no orbs. Cinnamon powder has a particle width of about 70 microns.
2. I have done tests photographing while vacuuming, which should have raised dust levels to as high as 100 microns. These tests produced no orbs greater than 2 percent of the original photo width.
3. I have done tests photographing steam produced by photographing in a steam-filled bathroom. This should have created particle sizes of about 300 microns. No orbs were observed.
4. I have done tests photographing mist sprayed in front of the camera, mist from a plant sprayer. This should have created particle sizes of between 100 and 500 microns. This produced a few very small “orbs” (really just droplets), but none that were “conspicuous” as defined above (none greater than about 3% of the original photo width).   

So based on these tests (which all used flash photos), I can conclude that  when using a normal camera setting (not “closeup photography” settings), you need a particle size of at least about 1000 microns to get a natural dust or vapor orb that is “conspicuous” as defined above (having more than about 3% of the original photo width). There is an entirely separate reason for drawing such a conclusion. No camera expert thinks that dust particles can be photographed within about 2 inches of the camera lens, so those who maintain that orbs are produced by dust tell us that dust is being photographed in a little “orb zone” area a few inches from the camera lens, in front of it.  Such an area would have a length that could not be smaller than about 30 millimeters, about the width of a half dollar coin. So if a dust particle were to appear in such an area blocking more than 3% of the original photo width, how big would it have to be? Apparently about 3 percent or more of this small area that is no smaller than 30 millimeters long – in other words, about a millimeter (the same as 1000 microns) or larger.  If one assumes an even larger "orb zone" width of greater than 30 millimeters, than an ever larger particle size would be needed to block 3% or more of the photo width. 

So both the results of experiments and camera field considerations lead us to the conclusion that under normal camera settings (not close-up photography settings) you need a particle size of at least about 1000 microns for some dust or water particle to produce a conspicuous orb in a photograph (one that is more than about 3% of the original photo width). But the particles of dust in ordinary air do not have such a size. Instead they have a size about 1000 times smaller, a size of only about one micron or less. This is why when skeptics claim that photos of prominent orbs taken in ordinary air are showing particles of dust, they are off by a factor of 1000, and are making a claim as wrong as the claim that you can buy a shiny new car for $20.

Could it be that when someone photographs an orb they might be photographing the “visible heavy dust” listed in my chart? No, that refers to the kind of dust you get in things like a steel foundry, a building collapse, or a volcanic eruption – dust so thick you can see the particles in front of you, and feel the particles collecting on your skin. Particles larger than about 10 microns can be seen with the eye.

Judging from this link which gives results from a fancy electronic particle counter, we should not at all expect particles of more than 10 microns to be floating around in typical air in residences or offices, and the particles in such air are mostly less than 1 micron.

But could it not be that when you are photographing an orb, you are photographing some relatively large particle of dust raised by some event that happened a few hours ago? No, it is not possible. This is because particles of dust larger than 10 microns always settle to the ground fairly quickly. This is shown by the chart below, derived from a chart at this URL.

Particle Size (Microns)	Settling Velocity (How Fast the Particle Falls)	Settling Velocity (Meters Per Minute)
0.1	.0000865 centimeters per second
1	.0035 centimeters per second
10	.306 centimeters per second	.18 meters per minute
100	.262 centimeters per second	.157 meters per minute

As we see from this chart, it takes only about six minutes for a 100 micron particle to fall a meter (about 3 feet), and dust particles of 1000 microns or larger have about the same settling velocity. While the dust particles in ordinary air (too small to produce orbs) take quite a while to settle to the ground, all of the larger dust particles above 10 microns settle to the ground fairly quickly at a rate of about a meter per six minutes. That means that unless some dramatic dust-raising event occurred very close to you within about 10 or 15 minutes of the time you took your photo (such as someone knocking out a wall, beating a rug with a stick, or toppling a large book case), there is no significant chance that conspicuous orbs produced in your photo are caused by dust.

This link has 11 photos of orbs that are more than 10 percent of the original photo width. How large would a dust speck have to be in order to produce such a large orb? It would have to be about 10,000 microns, larger than the width of a pencil (almost as wide as a dime). Such dust simply doesn't exist, not even in buildings that are being demolished. It is generally agreed that the maximum size of heavy dust is only about 1000 microns.

It would seem that our skeptical friends who claim that most orbs are just dust simply have not bothered to do their homework. Judging from their web sites, they apparently haven't done the experiments they should have done, and apparently haven't bothered to thoughtfully research the size of particles. So it's not surprising they've come up with an answer that is off by a factor of 1000.

If you go to one of the leading web sites of the “orbs are dust” skeptics, you will find some revealing text in which the author pretty much “gives away” that he doesn't seem to think dust in ordinary air is remotely sufficient for producing orbs. In a page called “How to Take Great Orb Pictures,” the author makes this revealing recommendation on how to photograph natural orbs that are just dust:

The basic idea is to drop or spray small particles close in front of the lens of the camera while taking flash pictures of an object beyond. This should yield orbs. Various solids (like flour, cinnamon, etc) can produce some pleasing, typical-looking orbs.

Here the writer revealingly seems to give away that he doesn't actually believe that ordinary photo conditions are anywhere near sufficient to produce natural orbs caused by dust. He asks us instead to create some ridiculously extreme and preposterously unnatural conditions in hopes that this would produce orbs, conditions that would create particle sizes 1000 times greater than in ordinary air. (I've tried the cinnamon test, and it doesn't produce conspicuous orbs.)

Such a recommendation is, of course, ridiculous. A theory that can only explain orb photos when people drop or spray particles in front of the camera is worthless for explaining 99% of all orb photos, which were not taken under anything like such absurdly extreme conditions.

The bottom line here: the orbs in the great majority of the better orb photos on the Internet are not photos of dust, because they were almost all taken in ordinary air, air in which the average dust particles are 1000 times too small to produce conspicuous dust orbs. 

Postscript:  See this post for a mathematical analysis comparing the size in front of a camera and the size of particles in the air. The analysis finds that the "blockage fraction" of a particle of dust in typical air is way too small to produce noticeable orbs.  The analysis also explains why neither pollen nor common water vapor can explain.orbs.