FOMA Ortho 400 is a special orthochromatically sensitized (this means: not sensitive to red!) black and white negative film. It is characterized by good resolving power and contour sharpness, fine grain and high maximum density of the silver image. Its high optical sensitivity enables to take photographs even in adverse light conditions and using shorter exposure times. The nominal optical sensitivity of the film is ISO 400/27°, but its wide exposure latitude provides very good results even when overexposed by 1.5 EV (ISO 160/23°) and underexposed by 2 EV (ISO 1600/33°). In case of exposure with lower light temperature than daylight (2700-2400 K) is recommended moderate adjustment of the exposure by 0,1-1 EV, especially by underexposure of the film (El 800 ISO and higher) with an absence of modification of development time (push process). Thanks to its typical tonal character, this orthochromatic type of the film is particularly suitable for artistically stylized portrait photography. FOMA Ortho 400 has a high level of the spectral sensitivity in green part of the visible spectrum, which is particularly advantageous when taken photographs of the landscape motifs and sceneries (forest greenness of the leaves of trees, bushes, etc.). For making positives, the enlarging and contact copying black-and-white papers are recommended, e.g. Fomabrom Variant, Fomaspeed Variant, Fomatone MG Classic, Retrobrom Sp, etc.

Specs

This and more information can be found in the manufacturer's datasheet