Accession Number : ADA016924

Title :   Engineer Tests of 2.5X Reduction Printer.

Descriptive Note : Technical rept. Apr-Oct 74,

Corporate Author : ARMY ENGINEER TOPOGRAPHIC LABS FORT BELVOIR VA

Personal Author(s) : Myers,Frederick C.

Report Date : APR 1975

Pagination or Media Count : 45

Abstract : The report covers the results of Engineer Tests on the 2.5X Reduction Printer, fabricated under contract by Latady Instruments, Inc., for production use by the DMA Topographic Center (DMATC). The printer was developed to give DMATC the capability of reducing 6.6-inch wide, high resolution, roll film imagery input to 70mm-wide roll film imagery output, while maintaining high resolution and low distortion. The printer was tested against the approved DMATC technical characteristics using a test belt containing a wide variety of photographic test subjects as inputs, such as low-contrast resolution targets, gray scales, calibrated grids, step wedges, and good quality large-scale imagery. The report concludes that the printer meets all the requirements of the Technical Characteristics, with the exception of resolution. The printer produced an average resolution of 103.5 lines per mm (2:1 TOC contrast), while a minimum of 130 lines per mm (2:1 TOC contrast) was required. The problem of Newton rings on the output film can be reduced by placing tape at the two outside edges of the input glass drum. Total elimination of the Newton ring problem will require a major redesign of the optical system to prevent the scattering of light between the outside surface of the glass input drum and the surface of the input film.

Descriptors :   *Projection printers, Reduction, Film transport systems, Photographic film, Engineering

Subject Categories : Photography

Distribution Statement : APPROVED FOR PUBLIC RELEASE