I am using a new flash(YN560) on the EM5. Doing some test shots, I'm getting this line of demarcation for some reason. I'm using the variable 14-54 MKII, have tried different zoom settings on the flash, different intensity, etc. Is there something I need to do to camera settings? Help please? The photo was shot @ 54mm at approx. 6'. Update: I think I figured it out. Shutter speed is to high. Looks like I can only go to 1/400 or so.