Ilford HPS

HP5 plus
Maker	Ilford Photo
Speed	400/27°
Push	3200/36°
Type	B&W print
Process	Gelatin-silver
Format	35mm, 120, sheets, disposable camera
Application	General
Introduced	1989

HP5
Speed	400/27°
Type	B&W
Introduced	1976
Discontinued	1989
Replaced by	HP5 plus

HP4
Speed	400/27°
Type	B&W
Introduced	1965
Discontinued	1989
Replaced by	HP5

HPS
Speed	400/27°, 800/30° (1960)
Type	B&W
Grain	coarse
Introduced	1954
Discontinued	1998
Replaced by	Delta 3200

HP3
Speed	125/22°, 200/24° (1952–53), 400/27° (1960)
Type	B&W
Introduced	1941
Discontinued	1969
Replaced by	HP4

HP2
Speed	200/24°
Type	B&W
Introduced	1939
Replaced by	HP3

HP
Speed	160/23°
Type	B&W
Introduced	1935
Discontinued	1939
Replaced by	HP2

HP is a cubic-grain black-and-white film from Ilford Photo with a long history. It originated as Hypersensitive Panchromatic plates in 1931. Since then it has progressed through a number of versions, with HP5 plus (HP5+ for short) being the latest. The main competitor of Ilford HP5 Plus is Kodak Tri-X 400.

HP3 went through two speed changes in its history, but only one actual change to the emulsion. In 1960 the 200 ISO/ASA emulsion was relabelled as 400 ISO/ASA with no change to the product. The 200 ISO/ASA speed included an exposure safety margin, but with improvements in light meters this was deemed unnecessary, thus the speed was revised up to 400 ISO/ASA.

On September 23, 2005 Ilford reintroduced its black-and-white single-use camera which includes 27 exposures of HP5 plus film.

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Wikipedia