Thomas Rudolphus Dallmeyer (1859-1906), second son of John Henry Dallmeyer (1830-1883); assumed control of family optical equipment and camera manufacturers J H Dallmeyer in the 1880s; one of the inventors of the telephoto lens in 1891; wrote Telephotography, 1899 and was president of the Royal Photographic Society, 1900-1903.