Contrary to what is written in http://community.avid.com/forums/t/59215.aspx (for MC 7) I cannot export a full HD single frame (1920x1080) from MC 8.4.4.If I export as JPEG or TIFF (no compression) the resulting picture is always 720x480.
In earlier versions of MC, exporting 1920x1080 single frames was possible.