hand, some (including Paranormal Investigators/Researchers) believe that some orbs are real. True evidence of spirit activity. On the other hand, there is a growing number of Paranormal Investigators/Researchers who believe orbs are nothing more than dust. Little airborne particles of dust. And, you also have those who are right in the middle. Orbs are also referred to as plasmoids, light spots, spheres, balls of light, and Basic Life Forms.
The orb phenomenon is really a modern day puzzle. If we look back to the late 1990's, many people have been capturing strange anomalies on their cameras, and not surprisingly, many orbs were captured using consumer digital cameras. Digital cameras did not really hit the mass market until the late nineties.
Before the big " I have GOT to get a digital camera" phase, 35mm cameras, (still my camera of choice!) 126 and the 110 pocket camera, and let us not forget the Polaroids, were the norm. And orbs were certainly not a common phenomenon! Even today 35mm cameras yield almost zero orbs, and digital SLR's greatly minimize them. As consumer compact digital cameras get smaller, the reports of orb phenomenon increases due to the short distance of the flash to the lens.
So which direction to go? Believer? Skeptic? Or somewhere in the middle? As a serious Paranormal Investigator/Researcher, think for yourself.
Is it possible that spirit orbs do exist? It is as possible as anything else in this field.
My opinion? Orbs are paranormally irrelevant, and should be looked at as an annoyance.
The scientific explanation of orbs is to think about your basic knowledge of photography. Camera out of focus? Your image will be. When an orb is captured on a photograph, you probably have your camera set on auto-focus and have clicked a shot of a room. Everything is in focus, except you had a dust particle floating close to your lens, or far from your lens. Either way, you will see a reflection of the camera's flash from that particle! Same is true with moisture in the air. Keep this in mind, too, no room is dust free! Dust is everywhere and can show up randomly, especially in digital photos. So, the weight of evidence in explaining orbs is overwhelmingly natural and scientific.
Many orbs can appear to be paranormal, but turn out to have a natural source/explanation as you continue to examine. This is considered a false - positive. This is a term used in reviewing evidence that describes a natural occurrence misidentified as a paranormal phenomenon. For example: there is sporadic banging sounds that seem to have a paranormal source, but upon investigating, it is the furnace. The vast majority of orbs are false - positives. Always approach and review investigation evidence such as photos and videos from the initial standpoint that they contain false - positives.
As a serious Paranormal Investigator/Researcher, I can't fall into the dubious beliefs just because they are popular. At the very least we have to discover some kind of evidence that will lead to a rational conclusion regarding the validity of spirit orbs. We do have this on other areas, like EVP's, but with orbs, who can prove that they are spirit generated? Nobody. So for all intent purposes, orbs are paranormally meaningless and insignificant. If spirit orbs exist, they are rare and only subjective evidence can link them to spirit activity.