This camera wasn't always evil. When an inventor (to his day unnamed) put the finishing touches on the camera, it was the latest in photo technology. But before he could unveil his invention, his lab partner, Dr. Fritz Fredericks (a.k.a. Spidey), stole the camera to take credit for the invention-and to enjoy the fame and riches that would come his way. The inventor stopped Dr. Fredericks' plan by cursing the camera for all eternity.
Whenever a photo of a person or object is taken with the camera, the photo produced will instead depict that person or object in the future after having suffered a fatal, or at least harmful and/or disastrous, event (i.e., a car crash, a heart attack or a fall). The dangerous accident depicted in the photograph will afterwards come true after a varying length of time; the time can be anything between just after the photo was taken, or can be days - weeks later. According to Spidey, the camera has the power to steal souls and is completely indestructible.
The Camera cannot move on its own and cannot force anyone to find it and use it. As long as it is well hidden, its evil powers are useless.