I discovered a problem when out shooting with my new Shen Hao 6x17 back. Every time I would compose a vertical object in the middle of frame, such as a lighthouse, church, tree, etc, then pan the camera to place the object more towards the edge of frame, the vertical object would tilt heavily towards the middle of the frame. Is there an easy way to overcome the leaning vertical problem? I'm using a 90mm lens, so camera movements are virtually non-existant. I found I had to leave these objects very close to the center of the frame, which looked terrible composition wise.