High-speed black-and-white negative film Ilford's Delta 400 Professional uses core-shell crystal technology to produce high sharpness with a fine, uniform grain structure. When developed in typical black and white chemistry, it has a nominal sensitivity of ISO 400/27°, which makes it ideal for handheld photography and use in challenging lighting situations. This adaptable film also has a wide exposure latitude and a tonal range that can be rated between EI 200 and EI 3200 and pushed or pulled during development to maintain constant contrast.