Methods used with SFRplus chart, Light box exposureds and Imatest Master

Tests conducted with the SFRplus chart were photographed with illumination from two modeling lamps each at 45 degrees angle. The images were taken as raw files with a Panasonic GX1 camera at ISO 200. Raw files were converted to high resolution tifs with Adobe Raw Converter. Tif's were analyzed with Imatest Master. Images were analyzed with a 13 region of interest pattern. MTF50 values were summarized as a weighted mean (center - 1.0; part-way - 0.75; corner - 0.25). Central MTF50 and chromatic aberrations were also determined with Imatest.

Photographs were also taken at infinity of an evenly illuminated white box with aperture wide open than at each full stop until f/8. Light drop off was measured with Imatest.