MustHD field monitor can work well with Canon 5D Mark III. We had a full test for it with our monitors. Our monitor has many advantages, like the sun-hood, HDMI locker, three battery plates options powered  and  high quality picture. Our focus assist is simply by adding white lines on the shape in the pictures.  We do not have color peaking at the moment, which we need to improve in the future. The camera mode can help you to get the full screen display, no distortion and no black clip when starting video record.

MustHD Field Monitor with Canon 5D Mark III

MustHD Field Monitor with Canon 5D Mark III

MustHD Field Monitor with Canon 5D Mark iii

MustHD Field Monitor with Canon 5D Mark IIII

MustHD Field Monitor with Canon 5D Mark iii