[luckystar1992]

As the title,thanks.

[luckystar1992]

P.S.:我係指英文的係全寫

[zeusho]

The International Organization for Standardization (ISO), based in Geneva, is a worldwide federation of national standards bodies from over 150 countries, one from each country. ISO is a non-governmental organization established in 1946.

[zeusho]

Conventional camera film is rated using the International Standards Organization (ISO), which determines the film speed. The higher the ISO number, the "faster" the film, meaning the less light needed to take a picture.

[pauljr]

International Organization for Standardization (ISO)

ISO film speed scales

The standard known as ISO 5800:1987 from the International Organization for Standardization (ISO) defines both a linear scale and a logarithmic scale for measuring film speed.

In the ISO linear scale, which corresponds to the older ASA scale, doubling the speed of a film (that is, halving the amount of light that is necessary to expose the film) implies doubling the numeric value that designates the film speed. In the ISO logarithmic scale, which corresponds to the older DIN scale, doubling the speed of a film implies adding 3° to the numeric value that designates the film speed. For example, a film rated ISO 200/24° is twice as sensitive as a film rated ISO 100/21°.

Commonly, the logarithmic (DIN) component is omitted from film speed ratings, and only the linear component is given (e.g. "ISO 100"). In such cases, the quoted "ISO" rating is in effect synonymous with the older ASA standard.

GOST (Russian: ⑷???) is a pre-1987 linear standard used in the former Eastern Bloc. It was almost, but not quite identical to the ASA standard. After 1987 the GOST scale was aligned to the ISO scale. GOST markings are only found on pre-1987 photographic equipment (film, cameras, lightmeters, etc.) of Eastern Bloc manufacture.


For futher information, please reference:

http://en.wikipedia.org/wiki/Film_speed

[micros]

國際標準化組織. International Organization for Standardization (ISO)

1946年設立 於日內瓦的國際專業組織，從事所有科技與非科技領域內的標準化工作(電氣及電子工程的 標準化。

以係菲林速度上﹐唔同地方有各自標準。
而家最通舛o既標準就係由 International Organization for Standardization 所定﹐亦即係我地成日講o既 iso。

http://de.wikipedia.org/wiki/Filmempfindlichkeit

http://t-photo.com/QK01002.htm