Researchers identify photographers by eye reflections
2 January 2014 Last updated at 15:33 GMT
Photographers can be identified by reflections in the eyes of people in the photo, according to a study.
Researchers used high resolution images produced by modern digital cameras to identify photographers and bystanders, by zooming in on images of eyes.
It is hoped the process could be used to identify the photographer in crimes in which the victims are photographed.
Dr Rob Jenkins, who led the University of York research, told BBC Radio 5 live's Up All Night: "The eye is very reflective... it's like a little black mirror but it's very small so you have to get in pretty close."