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The picture shows an ASA/DIN conversion in a 1952 photography book [70] in which 21/10° DIN was converted to ASA 80 instead of ASA 100. Some classic camera's exposure guides show the old conversion as they were valid at the time of production, for example the exposure guide of the classic camera Tessina (since 1957), where 21/10° DIN is ...
The sunny 16 rule can be used in varying light by setting the shutter speed nearest to the ISO film speed and f-number according to a generalized exposure table, as: [3] [4] Tessina with exposure guide plate from the 1960s. At that time, DIN 21 was equivalent to ASA 80. After 1983, DIN 21 was ASA 100. [5]
Film speed describes a film's threshold sensitivity to light. The international standard for rating film speed is the ISO scale, which combines both the ASA speed and the DIN speed in the format ASA/DIN. Using ISO convention film with an ASA speed of 400 would be labeled 400/27°. [29]
Note that the times are approximate, and vary between different films and ASA numbers, but the table shows in general how the exposure time is adjusted. In photography, reciprocity is the inverse relationship between the intensity and duration of light that determines the reaction of light-sensitive material.
The ASA (as for American Standards Association) photographic exposure system, originally defined in ASA Z38.2.1 (since 1943) and ASA PH2.5 (since 1954), together with the DIN system (DIN 4512 since 1934), became the basis for the ISO system (since 1974), currently used worldwide (ISO 6, ISO 2240, ISO 5800, ISO 12232).
An example of the use of f-numbers in photography is the sunny 16 rule: an approximately correct exposure will be obtained on a sunny day by using an aperture of f /16 and the shutter speed closest to the reciprocal of the ISO speed of the film; for example, using ISO 200 film, an aperture of f /16 and a shutter speed of 1 ⁄ 200 second. The f ...
Download QR code; Print/export Download as PDF; Printable version; In other projects ... DIN ISO 6; DIN ISO 216; DIN 276; DIN 323; DIN 476; DIN 1025; DIN 1451; DIN ...
The 1942 ASA exposure guide, ASA Z38.2.2-1942, featured a dial calculator, and revisions in 1949 and 1955 used a similar approach. An alternative simplification also was possible: ASA PH2.5-1960 proposed extending the concept of exposure value to all exposure parameters. Taking base-2 logarithms of both sides of the exposure equation and ...