When ghost hunting, cameras are used for a couple of reasons: to document any possible paranormal activity, and with the hope of capturing a spirit on camera. Historically, spirit photography took off in 1861 when William H. Mumler accidentally created one of the first "ghost" photos after he reused a plate from a previous photograph that wasn't properly cleaned. The following photo had the shadowy figure of a girl from the previous photo, which he showed to a spiritualist friend, not admitting the real cause of it. Mumler said of this "Not at that time being inclined much to the spiritual belief myself, and being of a jovial disposition, always ready for a joke - I concluded to have a little fun, as I thought, at his expense." This simple prank birthed an entire industry of fraudulent spirit photographers which would eventually be exposed. Today, ghost hunters still use cameras in the hope of capturing that classic spirit photo. But before you go snapping photos and looking for that next big piece of evidence, take note of some positive and negative aspects behind the different cameras on the market, and how and why they are theorized to work.
Digital v.s. Polaroid Cameras
Digital and film cameras both have their perks: digital cameras allow us to take an almost unlimited amount of photos and videos while ghost huntings, and you don't have to worry about wasting costly camera film. But some ghost hunters theorize that the materials and metals that make up camera film, like in a classic polaroid camera, can interact with the energy that we believe entities are made out of/emit. This would mean that spirits are more likely to show on film than on a digital camera, and is why some ghost hunters still gravitate towards older cameras for their investigations.
There are other downsides to both that influence the type of camera you might want to use more when visiting a haunted location. Damaged film, dust on camera rollers, and over-exposure on camera film can all cause "anomalies" (usually blueish or white spots and streaks) to show up on developing camera film and are often mistaken as being paranormal in origin. When it comes to digital cameras, photo editing and fake spirit photographs are unfortunately all too common across paranormal television and the internet, which makes accepting photos and video as true evidence that much more difficult.
A universal issue to the use of cameras in ghost hunting is the existence of orbs as a form of spirit photography. Orbs are one of the most commonly reported paranormal phenomena caught on camera, but this is typically caused by dust/dirt that is being illuminated by a cameras flash, whether it be film or digital. Dust and dirt will appear as white, slightly glowing "orbs" that range from opaque to somewhat transparent.
Pareidolia is another issue with spirit photography across the board: our own perception can influence how our brain interprets something, which can cause us to see familiar patterns among an image that is difficult to interpret. When ghost hunting, pareidolia is often responsible for making us to see facial patterns in fuzzy/grainy/low-quality photos.
Full Spectrum Cameras
Full Spectrum cameras see partially into the UV light spectrum, which is beneath the visible light spectrum of the human eye. Most cameras are made with filters that keep UV light out of the camera lens, otherwise the colors in the photos/videos we take wouldn't match what we see with our own eyes. (UV light adds a pinkish/purple hue to everything, and is produced by the sun.) For full spectrum cameras, these filters are removed or they are made without these filters in the first place. It is believed that spirits can sometimes be seen in this spectrum, but like many theories in the paranormal, we don't exactly know how or why this would be the case. Some animals can see partially into this spectrum (like cats) so this belief might come from animals who, according to some lore, are believed to be more in-tune with the spirit world and may be able to see these entities more easily than us. In an attempt to make a spirit more likely to show on camera, some ghost hunters seek full spectrum cameras in the hope that this theory is true.
Infrared cameras, also commonly known as night vision cameras, use infrared light (which is above our visible light spectrum) to allow us to see in the dark without emitting a light that is visible to us, and are another favorite device among ghost hunters. Paranormal activity can happen during any time of the day, but most ghost hunts are carried on at night because there is less noise from pedestrians and cars that might be passing by. These cameras can also aid ghost hunters who favor old, abandoned locations with no running electricity, allowing the ghost hunters to see what is in front of them on screen without the use of a camera flash or flashlight. If a location does have running electricity, they might shut off the power completely to eliminate the presence of EMF (electromagnetic fields) that can interfere with other ghost hunting devices.
Lore surrounding spirits that are more present at night might also contribute to some ghost hunters knack for night-time investigating, especially during the witching hour. Deprivation of senses, like sight, might also help someone be more in-tune with what they feel and hear while investigating. It is worth mentioning that investigating in complete darkness can be unnecessary and risky considering that uneven floors and narrow, old staircases could lead to injury if you were to trip and fall. Ghost hunting in the dark is also sometimes done, especially for paranormal TV, to aid in the eerie aesthetic of being in the pitch darkness while in the presence of spirits.
Thermal Imaging Cameras
Cold-spots are commonly experienced when dealing with a haunted location, and are believed to be the sign of a spirit manifestation. Because of this phenomena, utilizing cameras that show the temperature of the items and environment around you have become another go-to for some ghost hunters. Thermal imaging cameras work by measuring the infrared energy, or heat signature, of whatever is in front of it. Warmer temperatures show as warmer colors - yellow, orange, and red. Cooler temperatures show as cooler tones like green, blue, and purple. Not only could this theoretically allow us to visually see a cold spot, but it could also allow us to see entities themselves which some believe are also generally colder. They can also help us find natural sources of a cold spot, like a drafty window, or the poorly insulated area of a wall or floor.
Have you ever watched a ghost hunting show and seen a camera screen that produces stick figures over humans and supposed spirits that are present? That device is known as the SLS camera, which utilizes the Kinect sensor from Xbox systems. The Kinect works by projecting a depth-sensor in front of it which will map out a room, and are programmed to look specifically for anything human-shaped. Some Xbox users were unsettled when their Kinect would tell them someone else was in the room with them. This led to theories that the Kinect was seeing ghosts, but the reality of the situation is much less scary: when you have a piece of technology that is specifically programmed and designed to try and find human-like shapes in front of it, false positives will, without a doubt, happen on occasion. This is why you will usually see these stick figures stuck to walls and items, and not free-moving like a person does. Today, some crafty paranormal enthusiasts have fixed Xbox Kinects to cameras and screens, creating what we now call the SLS (Structured Light Sensor) camera.
Some SLS camera apps for your cell phone have popped up on the market, but be cautious of how they work as well. Most utilize the same technology in your phone as Snapchat, Instagram and TikTok filters, so they are far less accurate than that of the Kinect and tend to produce near-constant false positives.
CCTV (Closed-Cirsuit Television), also commonly known as video surveillence, are cameras that film to a limited number of monitors, and are typically used to monitor ones home or business. You will see a lot of CCTV footage circulating that claims to have captured evidence of the paranormal. Although this may sometimes be the case, the anomalies or spirits captured on these cameras are usually nothing more than (living) humans, animals, or insects that are given an odd appearance due to the low quality of most CCTV systems. Many of these cameras utilize fairly low frame rates, which is the number of frames recorded per second. Someone walking by a camera with a high frame rate will look smooth and natural. But someone passing by a camera with a much lower frame rate can have a fuzzy and "glitched" appearance. You might only see the top or bottom half of this person, or they sometimes look to have disintegrated and vanished as they walk to the edge of the cameras field of vision. These can all potentially be caused by the cameras low frame rate, and whether it is motion censored or not. If the camera is motion censored and the subject walks out of the range of that censor, the camera may stop recording, and the subject "disappears". Other studies have shown that general poor quality video recordings, poor configuration of the cameras technology, and a lack of system integration are other common issues among CCTV systems. This makes them difficult to trust when it comes to producing true evidence of the paranormal.