ISO 6200 pdf download.Micrographics — First generation silver-gelatin microforms of source documents — Density specifications and method of measurement
1 Scope
This International Standard specifies a method for measuring densities of first generation silver-gelatin microforms. It specifies density values for different qualities of documents. It applies to source document negative-appearing microforms. It does not apply to microforms for technical drawings which are dealt with in ISO 3272-2, or to diazo and vesicular films which are the subject of ISO 81 26, or to COM microforms which are dealt with in ISO 851 4.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 5-1 :1 984, Photography — Density measurements — Part 1 : Terms, symbols and notations . ISO 5-2:1 991 , Photography — Density measurements — Part 2: Geometric conditions for transmission density . ISO 5-3:1 995, Photography — Density Measurements — Part 3: Spectral conditions . ISO 61 96-1 :1 993, Micrographics — Vocabulary — Part 1 : General terms . ISO 61 96-4:1 998, Micrographics — Vocabulary — Part 4: Materials and packaging. ISO 61 96-5:1 987, Micrographics — Vocabulary — Part 5: Quality of images, legibility, inspection. ISO 61 96-6:1 992, Micrographics — Vocabulary — Part 6: Equipment.
3 Terms and definitions
For the purposes of this International Standard, the terms and definitions given in ISO 5-1 and ISO 61 96 apply.
4 Method of measurement
Density shall be measured with a densitometer in conformance with the requirements of ISO 5-2 and ISO 5-3 for measurement of ISO standard diffuse visual density and having an aperture of diameter 0,5 mm to 3,0 mm.Each area measured should be of even density and completely cover the aperture of the densitometer. A target area can be provided for this purpose when making first generation microforms. The emulsion surface shall face the collecting head of the densitometer which is usually opposite of the illumination lamp. Density is usually measured on sample images. If density does not appear visually to be uniform within an image, it is recommended that further measurements be made at different places within the image.
5 Density specifications
Background density shall be as specified in Table 1 . All values specified are ISO standard visual diffuse densities. The background densities given in Table 1 are densities above base plus fog. Therefore, for all density readings, the value of base plus fog shall be subtracted to enable comparison with the density requirements specified in Table 1 . The base plus fog density for microforms with clear base shall be not greater than 0,1 0. Some silver-gelatin microforms have a tinted base (grey base for example). The base plus fog density for these films is often higher than 0,1 0 due to the higher density of the base. Where appropriate, specific recommendations from the film manufacturer should be followed for background density. Documents which contain fine-line details, or complex characters such as Chinese and Japanese, may require lower background density values than those specified in Table 1 , with a lower limit of 0,70. When the content of a document has areas of different qualities, the density to be achieved shall be dictated by the lowest quality.