Estimation of Certain Quality Characteristics of Plates for Process Work^*

* In this paper the results of investigations are described which have been obtained in four theses carried out at the Institute. This has imposed some limitations on the extent of the measurements. It is believed, however, that some of the results obtained justify the present publication, although they are not conclusive in all respects.

Abstract

Sensitometric criteria are proposed for measuring the “effective contrast” of photographic materials for line and halftone work. Methods of estimating the resolving power of materials in line photography and of dot quality in the halftone process are described. A dot quality coefficient has been formulated. Good correlation between the contrast factor and resolution has been found for materials of conventional type but no correlation for the novel materials relying on infectious development (“lith”-type materials). A linear relation has been found between the dot quality coefficient and tne contrast coefficient for both conventional and lith-type materials. Latitude requirements for continuous tone copying of originals have been formulated. None of the materials tested satisfied these requirements.

Notes

* In this paper the results of investigations are described which have been obtained in four theses carried out at the Institute. This has imposed some limitations on the extent of the measurements. It is believed, however, that some of the results obtained justify the present publication, although they are not conclusive in all respects.