The following are examples and experiments of camera straps getting in the way of the picture - what straps look like when photographed. Kathy purposely created these photos to show how a camera strap can appear like a ghost vortex (or what some call a portal) within ghost pictures.
As you will see, the flash reflecting off of the strap can make a nice, white effect in the picture; but it can also appear black going across the photograph. We suggest that if you are going to go ghost hunting, it may be best to remove the camera strap or keep it around your wrist (if you do not want to remove it).