At some time, all of us have probably looked at a work of art and said, or at least thought, “I could do that.” But one of the simple beauties of this exhibition is that it presents us with incontrovertible evidence that artists and non-artists are not the same beast. We may be similar in outward appearance, but what goes on in our brains seems to be entirely different. In The Painter's Eye John Tchalenko (the technical side of the partnership) and Humphrey Ocean (the portrait painter) have …