David, my 75mm f8 Super Angulon covers 6x17 fine with no issues at the corners, Schneider's figures are on th e conservative side and the image circle is given as 181mm @f16 compared to 198mm @ f22 for the 5.6 version, and the Grandagon 75mm f4.5's 195mm @f22. To make the coverage of the faster lenses sound better they don't compare the same aperture

I know at least 2 others using the same 75mm f8 SA's on 6x17 with no problems, but none of us use movements.