Ilford's Delta 400 Professional is a high-speed black and white negative film featuring core-shell crystal technology in order to produce high sharpness with a fine, uniform grain structure. It has a nominal sensitivity of ISO 400/27° when developed in standard black and white chemistry, making it well-suited to handheld photography and working in difficult lighting conditions. This versatile film also features a broad tonal range and a wide exposure latitude, which is capable of being rated between EI 200 to EI 3200 and being pushed or pulled during development in order to maintain consistent contrast.