Cameras are commonly used throughout The Slender Man Mythos, especially in ARGs. In the Original Mythos, Slender Man could only be seen when someone took a picture using a camera. Since, they have played a vital role in the Mythos.
The camera's role between various iterations of Slender Man mythos has varied, however the most common reason one uses a camera in regards to Slender Man is for recording purposes in order to keep a detailed log either for oneself or for anyone who may happen upon the record after the original camera owner has gone missing. As such, video tapes and various recordings both serve as ways for the plot to progress while also allowing the viewer to see the events that the character is also involved in.
In modern depictions, Slender Man exhibits the uncontrollable ability to interfere with and alter technology around him, causing bizarre and often random alterations in the video including losing audio, video tearing, video blurring, freezing, audio blowout, color alterations (brighter, darker, changes in tint, changes in sharpness, removal of specific colors), skipping, and static in older camera models. It is important to note that not all cameras can emit static, as digital devices often have an auto-correct function that will often remove static and are more prone to video tearing. The difference in this can be seen between the static noise on Kate's camera from the Eight Pages versus the constant video tearing seen on Lauren's more advanced camera several decades later in Slender: The Arrival.
The reasons for a camera vary, however different series/games have different reasons
- In MarbleHornets, the main reason the camera exists is because The Operator causes debilitating memory loss, and the camera is the only surefire way to keep a record of what happened and allow the main characters to keep track of events.
- In Always Watching, Slender Man is only visible in a camera, and is otherwise totally invisible except when he does not want to be. As a result, the main characters require cameras to be able to see the entity following them. He also appears to be able to afflict people through cameras.
- In EverymanHYBRID, the camera is mainly for recording due to the danger of the entities that the crew are attacked by. It also serves as a method of communication by these entities, and cross-dimensional records between various iterations of the characters.
- Haunt's protagonist has a camera as he is a reporter trying to document the events that occurred at a facility. While the camera does have specific gameplay purpose such as disorienting the player or telling the player when Mark Slender is nearby, it also functions as the reporter's tool to allow him to document his findings.
- In Slender: The Eight Pages and Slender: The Arrival, the camera functions less as a tool for recording events and more as a way for the player to be able to tell that Slender Man is nearby and must be escaped from. In-universe its purpose is never really explained, however much like MarbleHornet's Alex Kralie, the main character Kate seems to do so purely out of paranoia, as her tape is only seen by Lauren and Lauren's tape is supposedly never seen by anyone except the player.