Standards Development

Scope

This part of ISO 18937 describes test equipment and procedures for measuring the light stability of reflection prints, both colour and monochrome, transparent or translucent films, and photographic prints for backlit displays., when subjected to a filtered xenon-arc light source simulating daylight through windows at specified temperatures and relative humidities.

General indoor display conditions described herein are intended to simulate common use conditions found in houses, apartments and other dwelling places where indirect lighting due to filtering (through window glass) and shading is often the principal illumination causing displayed photographs to fade. A UV-filtered xenon-arc lamp is found to provide a reasonable match to indirect, window-filtered daylight. 10), 20), 21) The specimen temperature is dominated by ambient conditions.

Simulated in-window display conditions are intended to simulate terrestrial daylight transmitted through standard architectural window glass (double glazing). A typical example of such display can be found when images are displayed in store windows, facing toward the outdoors, so that they may be viewed by people outside of the store.3),4)

NOTE It is recognized that in some instances, physical degradation such as support embrittlement, image layer cracking, or delamination of an image layer from its support, rather than the stability of the image itself, will determine the useful life of a print material.

General guidance is given in ISO 18937-1.

Purpose

For the purposes of this document, the terms and definitions given in ISO 18913 apply.