I have a question about the pixel shift setting. When I turn pixel shift on, the camera goes to "AF with shutter" (grayed in menu), in all modes, P,A,S,M. I prefer to use back button focus and not to use "AF with shutter." This does not make sense to me. Am I missing some other setting or it this the inevitable default? It's not hard to work around it by simply using the self time but I'm curious if anyone knows the reason for this behavior. Thanks.