Think you can spot the difference between an object - let's say, a ripped up playing card - and a hand drawn replica of it? Should be easy, no?
Well to test the theory, watch this incredible video by artist Mark Crilley backwards, starting with the two side-by-side - then go from the beginning to have your mind completely blown.
Crilley, a Michigan-based photo-realist painter and illustrator, is completing a series of YouTube 'realism challenges' that test his abilities and use his background as a teacher to help the rest of us get better at doodling.
Above is possibly his most impressive success yet, an illusion just as captivating as any magician's card trick we've ever seen.
What do you think?