London's National Portrait Gallery is always a good source of photography exhibitions. Currently on view are small case displays of
• the work of Gilbert Adams (1906–96), Bertram Park (1883–1972) and Yvonne Gregory (1889–1970)
• Alfred, Lord Tennyson, including work by Julia Margaret Cameron
• four platinum prints by Eveleen Myers
as well as plenty of other photographs. The NPG is always worth a visit.