20/20. But I kind of do this for a living.
I guessed most of them within 2-3 seconds to be honest. There are still plenty of tell-tale signs, although lots of very good work in there.
It's cool to see a new one of these, but I really don't know if including "digital paintings" is that useful/interesting. After all painters have been making photorealistic paintings for centuries. Digital technology has changed (or improved) that little to none. I'm much more interested in photorealistic *renders*. Which there are several of. But there the low(ish) resolution of the images serves to make it harder to tell they're CG, which seems a bit unfair. Looking at the final, larger images in the workflow threads usually reveals them as CG more easily. That being said I definitely appreciated that they linked to workflows for most of them, that's a really cool idea.
I've wanted to make a quiz/test site like this myself for a long time, in large part because none of them seem to ever include landscapes!
If you like this sort of thing, be sure to check out Autodesk's long-running, occasionally updated "Fake or Photo" site:
http://area.autodesk.com/fakeorfoto/- Oshyan
