Designed by Norman Koren of IMATEST LLC, the SFRplus test chart can be used to measure MTF, lateral chromatic aberration, distortion, and tonal response. The SFRplus chart offers alternative advantages over the traditional ISO 12233 charts including; much less wasted area; the ability to produce a map of sharpness over the sensor surface; better measurement accuracy due to the lower contrast; and full support for automated testing. The chart has 9 vertical columns and 5 horizontal rows of 10:1 and 2:1 contrast slant edge boxes; distortion bar at the top and bottom of the chart and a 20 step density gray scale.
The active area of the chart includes white space above and below the top and bottom distortion bars which is typically about 10% larger than the printed area. The white space is included because test images of the chart must include this white space in order to enable automated processing in Imatest SFRplus software.
The chrome on glass SFRplus chart has 7 vertical columns and 5 horizontal rows of 10:1 contrast slant edge boxes; distortion bar at the top and bottom of the chart and a star target for easy focusing.