Ilford Delta 100 Professional is a medium-speed, very fine-grained, high-sharpness, high-contrast black and white negative film.
The trick to the amazing sharpness and fineness of grain in this film is the Core-Shell Crystal Technology behind the grain structure of this film. It is a tabular grain structure, similar to Kodak's TMax line, which gives a very even, uniform grain structure. Delta 100 is an exceptional choice for anything requiring a high level of detail.
This film works very well rated between ISO 50-200, but is not as lenient to exposure errors as the traditionally-grained stocks like FP4 or HP5.