Details:
Summary:
Both the 0i/45i and 45i/0i geometries are used in densitometers, reflectometers, colorimeters and spectrophotometers throughout the photographic and graphic arts industries. Data from instruments of varying manufacturers and even among different series of a given manufacturer do not always agree. This investigation was undertaken to critically evaluate the geometry specified in ANSI PH2.17. A robust standard specification is critical because design of commercial instruments usually requires many trade-offs to best meet user needs. A precision densitometer with high resolution and stability was set up on an optical bench. The optical design was made large scale so that parameters of target area, cone and incidence angles are adjustable and centered on the current ANSI PH2.17 standard values. The illumination and collection systems were designed for field uniformity and flexibility rather than light efficiency. A precision densitometer with high resolution and stability was set up on an optical bench. The optical design was made large scale so that parameters of target area, cone and incidence angles are adjustable and centered on the current ANSI PH2.17 standard values. The illumination and collection systems were designed for field uniformity and flexibility rather than light efficiency.