Possible causes of light anomalies and orbs appearing on pictures include:
Moisture in the air, dirty lenses, dust, pollen, bugs, objects (like camera straps or fingers) in front of the lens, etc., and of course, 'faking' and manipulation. Since the advent of the digital camera, photographic captures of orbs are much more common, and many experts insist this is simply due to many lower quality cameras not being able to capture the pixelation required for the photo, thus leaving blank 'spots' in the photo, and also due to the usage of autoflash, which can cause all kinds of reflections and prisms that appear as orbs. Because cameras have become increasingly smaller, the lens and the built-in flash are often very close together which causes a reflection from the flash back into the lens and can create some strange light effects.
Wikipedia says: Spirit orbs are sometimes claimed to exist more densely around certain haunted regions, or to be the spirits of departed loved ones. These types of orbs are sometimes claimed to have faces, sometimes with discernable expressions and sometimes of recognizable persons. Some feel the size of an orb indicates how great of an impact a life force had in its lifetime.
But what about moving orbs? And orbs seen with the naked eye? Even if many orb photos can be explained away as mundane photographic 'accidents', there are numerous captures of moving light anomalies, which are harder to explain away as dust or other particles in the air, and there are many instances of people seeing orbs right in front of them.
I invite you to post your orb and ghostly photos to my paranormal forum MetaMystic, for discussion and study, with the following stipulations:
Please name/identify each of your photos. Include a description of the type of camera used, the conditions under which the photo was taken, location and any controls (i.e. if you took 2 more photos at the same time and there were no orbs on the other photos, etc.). Please describe any sensations you may have felt at the time the photo was taken, and any other pertinent information. We will invite discussion on the photos collected here and see what ideas we come up with.
bright blessings
Zsuzsana