If you want to make (as opposed to ‘take’ or photograph) photorealistic art, you can paint it, you can generate it out of a 3D application using mesh models and sets, you can composite it from multiple photos as I do, or you can make it out of vector art. I find the limitations on 3D renders (the modeling, the texturing, and the problems with fine/thin detail) to make that route not very satisfying.
Though I don’t have hands on experience with photorealistic (non-digital) painting, I have enough experience editing vector art to know that it is extraordinarily slow, painstaking work to do photorealism via that route.
Therefore, I find the collections you will see at the sites linked below to be truly amazing:
Paintalicious: A Pyrotechnic Showcase of Photo-Realistic Art
Basang Panaginip: The World’s Most Photorealistic Vector Art
I don’t think vector can compete with raster composites for true realism because it is too precise, too perfect, too … vector. But for commercial use, and for just plain blowing your socks off, this stuff is top of the line.
-Julie