NOVA | scienceNOW | Fake or Real?

Cloning
Where part of an image has been copied and reused

Compression artifacts
The more an image is compressed, the blockier or grainier it will appear. This blockiness or graininess should be consistent throughout the image.

Contact
Where two objects in an image meet and their effect on each other

Drop shadow
A shadow offset from an object or person in an image

Granularity
Refers to compression artifacts

Hot spot
A reflection of a camera flash or other light source, which creates a bright spot or spots in an image

Noise or speckle
Pixels or specks of an image that are the wrong color or shade

Red eye
Where the camera flash causes a person's irises to be red instead of black

Small white specularity
The white dots seen in people's eyes, which reflect the lighting in a room or outdoors

Seeing is no longer believing in our modern digital world. Powerful photo-manipulation software is available to anyone who seeks it. And according to digital forensics expert Hany Farid, improved forging technologies make it more important now than ever to look at photographs with a discerning eye. We asked Farid to scrutinize several photographs of NOVA scienceNOW host Neil deGrasse Tyson with different celebrities and then determine which were forgeries that we created.

Below, try your hand at differentiating doctored from untouched photos (acknowledging, of course, that Farid likely had a lot more technology and experience at his disposal than you do). Once you've made up your mind for each image, click on "Fake" or "Real" and then hear what Farid has to say about it. For tips on what to look for when examining photos for authenticity, see the glossary at left.


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Hany Farid is the founder of digital forensics, a scientific field designed to determine if digital images, audio, video, and other documents have been manipulated or altered in any way. He runs the Image Science Lab at Dartmouth College.

This feature was produced by Rima Chaddha with audio editing by David Levin.