ISO 18909:2022 pdf download – Photography — Processed photographic colour films and paper prints — Methods for measuring image stability.
1 Scope This document describes test methods for determining the long-term dark storage stability of colour photographic images and the colour stability of such images when subjected to certain illuminants at specified temperatures and relative humidities. This document is applicable to colour photographic images made with traditional, continuous- tone photographic materials with images formed with dyes. These images are generated with chromogenic, silver dye-bleach, dye transfer, and dye-diffusion-transfer instant systems. The tests have not been verified for evaluating the stability of colour images produced with dry- and liquid-toner electrophotography, thermal dye transfer (sometimes called dye sublimation), ink jet, pigment-gelatin systems, offset lithography, gravure and related colour imaging systems. If these reflection print materials, including silver halide (chromogenic), are digitally printed, refer to ISO 18936, ISO 18941, ISO 18946, and ISO 18949 for dark stability tests, and the ISO 18937 series for light stability tests. This document does not include test procedures for the physical stability of images, supports or binder materials. However, it is recognized that in some instances, physical degradation such as support embrittlement, emulsion cracking or delamination of an image layer from its support, rather than image stability, will determine the useful life of a colour film or print material. 2 Normative references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 5-2, Photography and graphic technology — Density measurements — Part 2: Geometric conditions for transmittance density ISO 5-3, Photography and graphic technology — Density measurements — Part 3: Spectral conditions ISO 5-4, Photography and graphic technology — Density measurements — Part 4: Geometric conditions for reflection density ISO 18911, Imaging materials — Processed safety photographic films — Storage practices ISO 18913, Imaging materials — Permanence — Vocabulary 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 18913 apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: — ISO Online browsing platform: available at https:// www .iso .org/ obp — IEC Electropedia: available at https:// www .electropedia .org/
4 Test methods — General 4.1 Sensitometric exposure The photographic material shall be exposed and processed in accordance with the manufacturer’s recommendations to obtain areas (patches) of uniform density at least 5 mm × 5 mm. This document requires measuring the changes in colour densities in minimum density areas, d min , and at a density of 1,0 ± 0,05 above d min . These changes are to be monitored in neutral areas, i.e. where the initial red, green and blue densities are approximately equal (above their respective d min , as well as in areas selectively exposed to produce the purest possible cyan, magenta and yellow dye scales 1) . These shall be made with the aid of appropriate filters (see Table 1). The desired density may be obtained from a single precise exposure or from a continuous wedge exposure. Alternatively, if it is more convenient (e.g. with automated densitometry), the starting densities of 1,0 above d min may be interpolated from other densities (one way to do this is described in Annex A).
ISO 18909:2022 pdf download – Photography — Processed photographic colour films and paper prints — Methods for measuring image stability
