ISO 6:1993 pdf download – Photography – Black-and-white pictorial still Camera negative film/process Systems – Determination of ISO Speed
1 Scope
This International Standard specifies the method for determining the ISO Speed of black-and-white nega- tive Camera films used for pictorial still photography. This International Standard applies to films processed in conventional chemicals and equipment, but also to those processed using special procedures such as those involving activators or heat for development. This International Standard does not apply to motion- picture, aerial photography, graphic arts, radiographic or micrographic applications, nor to negatives prod- uced in diffusion transfer Systems.
2 Normative references
The following Standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publi- cation, the editions indicated were valid. All Standards are subject to revision, and Parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most re- cent editions of the Standards indicated below. Members of IEC and ISO maintain registers of cur- rently valid International Standards.
3 Definitions
For the purposes of this International Standard, the following definitions apply.
3.1 exposure, H: The time integral of illuminance on the film, measured in lux seconds. Amounts of exposure are often expressed in logarith- mit terms
3.2 Speed: A quantitative measure of the response of the photographic material to radiant energy for the specified conditions of exposure, processing and im- age measurement.
4 Sampling and storage
In determining the ISO Speed of a product, it is im- portant that the evaluated samples yield the average results obtained by users. This will require evaluating several different batches periodically under the con- ditions specified in this International Standard. Prior to evaluation, the samples shall be stored according to the manufacturers’ recommendations for a length of time to simulate the average age at which the product is normally used. Several independent evaluations shall be made to ensure the proper calibration of equipment and processes. The basic objective in se- lecting and storing samples as described above is to ensure the film characteristics are representative of those obtained by a photographer at the time of use.
5.4.2 Processing specifications
The only processing specification required in this International Standard is that the density differente between Points m and n shall be 0,80 (see 5.6.3 and figure 1). No additional processing specifications are included in recognition of the wide range of chemicals and equipment used in processing black-and-white films. ISO Speeds provided by film manufacturers generally apply to films when they are processed in accordance with their recommendations to produce the photographic characteristics specified for the process. Process information shall be available from film manufacturers or others who quote ISO Speed. This shall specify the chemicals, time, temperatures, agi- tation equipment and procedure used for each of the processing Steps and any additional information re- quired to obtain the sensitometric results described. The values for Speed obtained using various pro- cessing procedures tan differ significantly. Although different Speeds for a particular film tan be achieved by varying the process, other sensitometric and physical changes tan also accompany the Speed changes. Generally, processes which yield higher ISO Speed will also increase the graininess of the negative and the final print.