Delta 100 Professional - Medium Speed ISO 100; - Superb image quality, precise rendition; - Core-shell crystal technology. For sharpness and freedom from grain, ILFORD DELTA 100 PROFESSIONAL is simply the best in its class - offering the photographer exceptionally fine grain and a level of sharpness rarely seen, resulting in outstanding clarity of detail and the most precise image rendition. Capable of superb image quality at its recommended rating of ISO 100/21, this film will also produce great results rated between ISO 50 and 200.