One of the leading theories concerning what orbs are and the one that I lean towards the most is that they are not the spirit at all. The orb is the energy being transferred from a source (i.e. powerlines, heat energy, batteries, people, etc) to the spirit so they can manifest. This may not even be a conscious thing the spirit is doing, just a natural way they get their energy. This would explain why the orbs are round balls. According to the laws of Physics energy being transferring like that would assume is natural shape of a sphere. This theory can also be tied into the EMF readings we get during spirit activity.
I always approach things with a bit of skepticism, so when I saw all these websites start showing off these photos as ghosts, I was just as weary as most of you. I just had to try it for myself. I took a 35mm camera that I had used regularly for 6 years in all types of lighting and weather and had never gotten an orb or other unexplainable photo before and went out with a few seasoned field investigators on a cemetery investigation. One of the investigators was psychic and she pointed out a few areas we should take photos, so I did. I also had ghost footsteps walkup behind me twice and I turned around quickly and took photos of the empty air. When I got my photos developed, I had these orbs and fog in those photos that I was told to take, as well as the footstep ones. All my other photos were normal. Coincidence?
Since we do not know what orbs truly are, just that they seem to be found mainly in areas where there is ghost activity, I will tell you what they are not. On a normal investigation there are about 10 people using 10 different cameras, 35mm and digital, and many speeds and brands of film. They all get their film developed at separate places. Let's say only half of these investigators get some orb photos. Are these water spots or dirt on the lens? That would mean that 5 people all had similar dirt on their lens and all 5 did not clean their lens either. Are these orbs film processing errors? Well the 35mm cameras all had their film developed in different locations and used different film so that is very unlikely. The digital cameras can't have film-processing errors. I am aware that some people feel that the orbs on a digital camera are an error in the digital processing of the image. When that error does occur in digital photos, the objects tend to be square in nature, not round and they cannot be semi-transparent, the pixel behind would have to be corrupted also. I will not even address the precipitation theory, no legitimate researchers takes photos in any form of precipitation. What about dust and dirt being stirred up? Can that be the cause of the orbs? If that were the case, I would think that there would not be normal photos in a sequence of photos from the same camera and location. All of the shots in a sequence should have the dust or dirt in it. We find that most orb photos do not appear in consecutive photos. All photographers present should get orbs if it is dust being stirred up as well.
These are just a few things for the skeptics to think of when they are condemning an orb photo as a fake or fraud and some things for investigators to consider when checking their photos for positives.