The Nisha Bay 1 Blue Filter can be used to decrease image contrast in select areas of an image while increasing tonal separation between blue-colored subjects versus yellow, orange, or red subjects when photographing using a film camera system with black-and-white film installed.
When using this filter, wavelengths of visible light that are apparent as yellow, orange, and red colors to the human eye are suppressed, while visible light associated with blue colors are able to more easily pass though the Nisha Bay 1 Blue Filter and into the lens it is mounted on. When photographing with this filter along with black-and-white film, blue-colored subjects within a scene are reproduced in lighter shades of gray than without a filter. Simultaneously, yellow, orange, and red subjects are rendered in darker shades of gray than if a filter was not used.
When applied to black-and-white photography, the decreased contrast provided by the Nisha Bay 1 Blue Filter can result in lightened skies as well as clouds with limited definition. Additionally, this filter can also increase the appearance of haze or fog caused by the bluish cast of daylight.