My Sigma 17-70 F2.8-4.5 DC Macro is producing Barrel Distortion when attached to my K7 (not that I have another camera to chech it aganist)
how do I correct it when the function is disabled for non pentax lenses on the K7?
The Photo attach is take at the 17mm FL of a 10mm grid with the front of the lens sitting at the minimum focual lenght about 2000mm from the page, spirit leveled on a tripod....
The second at 50mm FL