Experimental photography is the manipulation of techniques or technologies to depict the impossible. It often reuses existing techniques in new ways. Photographers face difficulties as equipment and materials become discontinued. Experimental photography includes four categories: historical, contemporary, traditional, and non-traditional. Mariah Robertson is a contemporary experimental photographer based in Brooklyn known for her manipulated digital images that violate photographic rules. Kayla Varley is a Los Angeles-based photographer who produces intimate black and white self-portraits that tell personal stories. Ronny Engelmann is a German photo artist who creates strange but wonderful manipulated images to depict his fantastical ideas.