Faces in the Static: Pareidolia, Orbs and Ghost Photos

Pareidolia is the tendency to perceive a meaningful pattern, most often a face, in something random or vague: two windows and a door that look like a startled face, a grinning electrical socket, a figure in the folds of a curtain. It is normal and almost universal. The brain is built to find faces fast. In a 2009 study, Nouchine Hadjikhani and colleagues recorded brain activity as volunteers looked at objects that happened to resemble faces and found that a face-sensitive region responded within about 165 thousandths of a second, almost as quickly as it responds to real faces. The face is seen first and questioned later, if at all.

A common explanation is that, for our ancestors, missing a real face in the undergrowth was far more costly than mistaking a shadow for one, so a brain that errs toward seeing faces is the safer design. The same tendency works on sound. People hear voices in the hum of a fan, running water or radio static, and once someone has been told which words to listen for, they hear those words much more easily. That is worth remembering when listening to recordings made with spirit boxes and EVP equipment. The broader habit of finding meaningful connections between unrelated things has its own name, apophenia, coined by the German psychiatrist Klaus Conrad in the 1950s.

None of this means a witness is foolish. It means everyone's perception has a default setting, and a face in a dark window or a shape in the shadows has to be weighed against it before it can count as evidence of anything else.

Since compact digital cameras spread around the turn of the century, flash photos taken at night or indoors have often shown translucent circles floating in the frame, called orbs, which some people take to be spirits. The usual cause is flash backscatter. When the flash sits close to the lens, as it does on compact cameras and phones, its light bounces straight back off tiny particles floating just in front of the lens: dust, pollen, droplets of moisture, snowflakes or small insects. They are far too close to be in focus, so each bright point spreads into a soft disc, sometimes with rings or a mottled texture that comes from the lens itself. Nobody in the room sees them, because the particles are tiny and the flash lasts a fraction of a second.

Backscatter orbs give themselves away. They appear in front of everything and never behind a solid object. They multiply in dusty, damp or freshly disturbed rooms and outdoors in rain, mist or snow. They change position from one frame to the next, and they disappear when the flash is switched off. A simple experiment reproduces them: shake a dusty cloth or mist a spray bottle in a dark room and take a few flash photos.

Other orb-like shapes have their own causes. Streaks and tails come from insects or raindrops moving during the exposure. Rings and blobs of colored light near a bright lamp are lens flare, internal reflections between the glass elements of the lens, which photographers have long called "ghosts" because they appear in the image but not in the room.

Ghost photographs are almost as old as photography. In the early 1860s William Mumler, a Boston engraver and amateur photographer, produced a self-portrait that seemed to show a faint figure, which he and others identified as a cousin who had died twelve years earlier. Followers of the Spiritualist movement hailed it, and Mumler became a professional spirit photographer, charging clients for portraits in which their dead relatives appeared beside them.

After he moved to New York he was put on trial for fraud in April 1869. The showman P. T. Barnum testified against him, and the prosecution presented a picture of Barnum apparently accompanied by the ghost of Abraham Lincoln, made by the photographer Abraham Bogardus, to show how easily such images could be produced. Mumler was acquitted, because the prosecution could not prove how he had made his pictures. His most famous image, of Mary Todd Lincoln with a shadowy figure resembling her late husband, dates from the early 1870s. Critics noticed that some of his "spirits" were recognizable as people who were still alive, and his photographs are now regarded as fakes, most likely made by double exposure.

A later case shows that intelligence is no protection. In 1917 two girls in Cottingley, in Yorkshire, photographed what appeared to be fairies, and Arthur Conan Doyle endorsed the pictures in The Strand Magazine in 1920. In 1983 the cousins, by then elderly, admitted that the fairies were paper cut-outs propped up with hatpins, although one of them maintained that the fifth and final photograph was genuine.

Many modern ghost photos come from the camera doing exactly what it was designed to do. In dim light a camera keeps its shutter open longer, and anyone who walks through the frame during that time comes out blurred and partly transparent, the same effect early photographers knew well. Phones go further. Night modes and other computational features merge several frames into one, so a person or pet that moved can appear doubled, cut off or as a see-through half-figure. Panorama mode stitches images together and can drop or duplicate limbs. In dark images, digital noise and compression produce blotchy textures in which the brain readily finds faces.

Ordinary objects contribute too: reflections in a window or a glass cabinet, breath on a cold night, cigarette smoke or vapor, a camera strap, a stray hair or a fingertip at the edge of the lens. Each has produced a well-circulated ghost photo at some point, and each can be recognized by someone who knows to look for it.

The newest problem is editing. Apps that add a ghost to any picture have existed for years, and generative image tools now make convincing fakes easy for anyone. That shifts the weight of a photo away from what the picture shows and toward where it came from: who took it, on what device, under what conditions, and whether the original file and the frames around it still exist. A photo that arrives as a screenshot of a repost, with no photographer to ask, can tell us very little no matter how striking it is.

Believers and skeptics can work through the same questions together, and the answers sometimes surprise both:

• Find the original file, not a screenshot or a repost, and look at its metadata: the device, the time, the exposure length and whether the flash fired.
• Ask what the photographer saw with their own eyes at that moment. Something seen and then photographed is different from something noticed later on the screen.
• Look at the frames taken just before and after. A real object should still be there; a dust orb or a passing person usually is not.
• Note the settings and modes: flash, long exposure, night mode, panorama, filters or editing apps.
• Try to reproduce it in the same place, with the same device, under the same conditions.
• Agree in advance what result would change your mind, whichever side you start on.

A photograph that survives every one of these checks is not proof of a ghost, but it is a genuinely interesting puzzle and worth recording carefully. Most do not survive them, and finding the ordinary cause is a result too.