I was at studio today.There is a distortion at photos with zoom. straight things appear bent.The same distortion in dng format is way less.
The only way I can see this happening is if the camera firmware is incorrectly applying the distortion correction. This could happen if the part of the firmware that does the correction thinks it's at a different zoom level.
Are you using the set_zoom function to change the zoom?
Do you still get the same effect if you use key press functions, like click('zoom_in') ?
If you shoot without zooming in, is the DNG more or less distorted than the jpeg?
Of course, if DNG works for you then you can certainly use it, but looking into the root cause might save you trouble elsewhere.
