*update* I may have been a bit hasty with my opinion on the CCTV ghost reported in The Metro. Bob Dezon has pointed out that a similar effect can be created using Adobe After Effects as demonstrated in this tutorial video that he sent to me.
‘Ghost’ caught on CCTV video at ‘haunted’ community centre in South Rouislip’ claims The Metro newspaper in big bold letters. Underneath is a video that supposedly shows the ghost in question on footage taken from a CCTV camera, accompanied by an account from the Caretaker of the Rouislip Community Centre who says
I was sitting inside the hall and noticed a figure on the front CCTV camera,‘I looked up at the screen and thought I saw a person but wasn’t sure so went out to check. I went outside and no one was there but I thought they might have quickly walked around the side of the building into the park so I just went back in. After downloading the CCTV footage I was surprised to see that the figure had been recorded onto the system. I can’t explain this.’
The effect seen in the video is possibly caused by something called ghosting, or ringing as it’s called by professionals in the film and CCTV industry. Basically, what we could be seeing is a replica of a transmitted image that is super-imposed on top of the main image. Some systems use one screen to show numerous camera feeds and this can be a product of such a set up sometimes. Ghosting can be caused by mismatched impedance on communication channels which causes reflections in analogue systems, or on digital systems when interlaced video is wrongly deinterlaced for output devices.