I'm using a Leaf Aptus22 back using the Leaf interface plate and sync cable on a RZ67 proII camera and seem to have an exposure issue. I did a test to confirm in max sunlight by adjusting shutter speed and aperture to maintain EV. When using 1/400 or 1/250 (to a lesser degree) the image comes out underexposed, while the slower shutter speeds maintain a consistent exposure over the entire range. It is also lens dependent. The 110mm isn't as affected as the 210mm or 65mm lenses. For example, the 210mm is rougly 2 stops underexposed if using 1/400 f4.5 vs 1/125 f8, while EV is the same. Also worth mentioning is that the 110mm lens shutter broke (it does not open) while testing, which could be a coincidence or not. Any suggestions?