This is a masterpiece by probably the most famous of spirit photographers, William Hope of Crewe. He gave thousands of sittings from 1905, improving earlier crude techniques which even spiritualists saw through. As shown above, Hope used double exposure - the sitter's plate being replaced by a prepared plate with an extra dressed in ectoplastic cheesecloth already on it. If the sitter was too vigilant, Hope used simpler chemical or flashlight techniques. 固opFoto