I have a feeling that this may be tilt but I just wanted a second (third and fourth!) opinion. It runs from the north east to south west but doesn't effect the north west nor south east.
If it hit everything equally I'd say field curvature but it doesn't.
IMO it is a combination of a tilt and some field curvature. Are you using a flattener Colin? I found that my ED f/7 doublet needs a flattener even with small Sony sensor.
IMO it is a combination of a tilt and some field curvature. Are you using a flattener Colin? I found that my ED f/7 doublet needs a flattener even with small Sony sensor.