In the early 1970s, a small group of photographers calling themselves the Co-Optic Group—including Martin Parr, Gerry Badger, Sirkka-Liisa Konttinen, and Stephen Weiss—set out to take picture-postcard snapshots of what the ‘real Britain’ looked like. Their results are by turns nostalgic and extreme, with deckchair kips, tobacconists and a child forever blowing bubbles in front of Enoch Powell.