photography Photography is the visual arts, art, application, and practice of creating images by recording light, either electronically by means of an image sensor, or chemically by means of a light-sensitive material such as photographic film. It is empl ...

, backscatter (also called near-camera reflection) is an

optical phenomenon Optical phenomena are any observable events that result from the interaction of light and matter. All optical phenomena coincide with quantum phenomena. Common optical phenomena are often due to the interaction of light from the Sun or Moon with ...

resulting in typically circular artifacts on an image, due to the camera's

flash Flash, flashes, or FLASH may refer to: Arts, entertainment, and media Fictional aliases * The Flash, several DC Comics superheroes with super speed: ** Flash (Jay Garrick) ** Barry Allen ** Wally West, the first Kid Flash and third adult Flash ...

being reflected from unfocused motes of

dust Dust is made of particle size, fine particles of solid matter. On Earth, it generally consists of particles in the atmosphere that come from various sources such as soil lifted by wind (an aeolian processes, aeolian process), Types of volcan ...

, water

droplets A drop or droplet is a small column of liquid, bounded completely or almost completely by free surfaces. A drop may form when liquid accumulates at the end of a tube or other surface boundary, producing a hanging drop called a pendant drop. Dro ...

, or other

particle In the physical sciences, a particle (or corpuscle in older texts) is a small localized object which can be described by several physical or chemical properties, such as volume, density, or mass. They vary greatly in size or quantity, from s ...

s in the

air An atmosphere () is a layer of gases that envelop an astronomical object, held in place by the gravity of the object. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosph ...

or water. It is especially common with modern compact and ultra-compact digital cameras. Orb photographic

Caused by the

backscatter In physics, backscatter (or backscattering) is the reflection of waves, particles, or signals back to the direction from which they came. It is usually a diffuse reflection due to scattering, as opposed to specular reflection as from a mirror, ...

of light by unfocused particles, these artifacts are also sometimes called orbs, referring to a common

paranormal Paranormal events are purported phenomena described in popular culture, folk, and other non-scientific bodies of knowledge, whose existence within these contexts is described as being beyond the scope of normal scientific understanding. Not ...

claim. Some appear with trails, suggesting

motion In physics, motion is when an object changes its position with respect to a reference point in a given time. Motion is mathematically described in terms of displacement, distance, velocity, acceleration, speed, and frame of reference to an o ...

Cause

Backscatter commonly occurs in low-light scenes when the camera's

is used. Cases include

nighttime Night, or nighttime, is the period of darkness when the Sun is below the horizon. Sunlight illuminates one side of the Earth, leaving the other in darkness. The opposite of nighttime is daytime. Earth's rotation causes the appearance of su ...

and

underwater photography Underwater photography is the practice of capturing images beneath the surface of the water, often done while scuba diving, but can also be done while diving on surface supply, snorkeling, swimming, from a submersible or remotely operated und ...

, when a bright light source and reflective unfocused particles are near the camera. Light appears much brighter very near the source due to the

inverse-square law In science, an inverse-square law is any scientific law stating that the observed "intensity" of a specified physical quantity is inversely proportional to the square of the distance from the source of that physical quantity. The fundamental ca ...

, which says light intensity is inversely proportional to the square of the distance from the source.Richard Ferncase.
Basic Lighting Worktext for Film and Video
'. CRC Press; 1992. . p. 66. The artifact can result from the

retroreflection A retroreflector (sometimes called a retroflector or cataphote) is a device or surface that reflects light or other radiation back to its source with minimum scattering. This works at a wide range of angle of incidence, unlike a planar mirror, w ...

of the light from airborne solid particles, such as

pollen Pollen is a powdery substance produced by most types of flowers of seed plants for the purpose of sexual reproduction. It consists of pollen grains (highly reduced Gametophyte#Heterospory, microgametophytes), which produce male gametes (sperm ...

, or liquid droplets, especially rain or mist. They can also be caused by foreign material within the camera lens. The image artifacts usually appear as either white or semi- transparent circles, though may also occur with whole or partial color spectra,

purple fringing In photography (particularly digital photography), purple fringing (sometimes called PF) is the term for an unfocused purple or magenta "ghost" image on a photograph. This optical aberration is generally most visible as a coloring and lightenin ...

or other

chromatic aberration In optics, chromatic aberration (CA), also called chromatic distortion, color aberration, color fringing, or purple fringing, is a failure of a lens to focus all colors to the same point. It is caused by dispersion: the refractive index of the ...

. With rain droplets, an image may capture light passing through the droplet creating a small rainbow effect.J. David Pye.
Polarised Light in Science and Nature
'. CRC Press; 2015. . p. 81.

Fujifilm , trading as , or simply Fuji, is a Japanese Multinational corporation, multinational Conglomerate (company), conglomerate headquartered in Tokyo, Japan, operating in the areas of photography, optics, Office supplies, office and Biomedical engine ...

describes the artifacts as a common photographic problem: Photographical orbs

In underwater scenes, particles such as sand or

plankton Plankton are the diverse collection of organisms that drift in Hydrosphere, water (or atmosphere, air) but are unable to actively propel themselves against ocean current, currents (or wind). The individual organisms constituting plankton are ca ...

marine life Marine life, sea life or ocean life is the collective ecological communities that encompass all aquatic animals, aquatic plant, plants, algae, marine fungi, fungi, marine protists, protists, single-celled marine microorganisms, microorganisms ...

near the lens, invisible to the diver, reflect light from the flash causing the orb artifact in the image. A strobe flash, which distances the flash from the lens, eliminates the artifacts.Nick Robertson-Brown.
Underwater Photography: Art and Techniques
'. Crowood; 31 January 2014. . p. 105. The effect is also seen on

infrared Infrared (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than that of visible light but shorter than microwaves. The infrared spectral band begins with the waves that are just longer than those ...

video cameras, where superbright infrared LEDs illuminate

microscopic The microscopic scale () is the scale of objects and events smaller than those that can easily be seen by the naked eye, requiring a lens or microscope to see them clearly. In physics, the microscopic scale is sometimes regarded as the scale betwe ...

particles very close to the lens. The artifacts are especially common with compact or ultra-compact cameras, where the short distance between the lens and the built-in flash decreases the angle of light reflection toward the lens, ''directly'' illuminating the aspect of the particles facing the lens and increasing the camera's ability to capture the light reflected from normally subvisible particles.

Paranormal claims

Some ghost hunters have claimed that orb shaped visual artifacts appearing in photographs are spirits of the dead. Such perceptions have been interpreted by

Michael Shermer Michael Brant Shermer (born September 8, 1954) is an American science writer, historian of science, executive director of The Skeptics Society, and founding publisher of '' Skeptic'' magazine, a publication focused on investigating pseudoscientif ...

as examples of agenticity. Prominent paranormal investigators such as

Joe Nickell Joe Herman Nickell (December 1, 1944 – March 4, 2025) was an American skeptic and investigator of the paranormal. Nickell was a senior research fellow for the Committee for Skeptical Inquiry and wrote regularly for their journal, '' Skeptic ...

have agreed with skeptic-debunkers' assessments that orbs result from natural phenomena like insects, dust, pollen, or water droplets.Joe Nickell.. p. 159.

References

External links

{{Parapsychology Digital photography Paranormal Science of photography

Cause

Paranormal claims

See also

References

External links