A Few Things About Microlines That Most People Do Not Know

The making and evaluation of an exposure series has been reviewed to show how halftone dots, microlines, and continuous tone steps change as a function of exposure. A history of microline test targets has also been presented. It can be shown why optimum resolution and dot-for-dot contacting occur at an exposure where the .30 continuous tone density step in the original reproduces again as .30 density. The relationship between standard photographic resolution targets (where the line to space ratio is 1:1) and microline targets (that use line to space ratios other than 1:1) has been discussed. Recommendations for practical exposure determination for film and platemaking have also been considered.