For the canon eos 5d digital slr camera the ee s focusing screen manual precision matte is designed for manual focusing with high speed lenses f28 or faster the ee s screen has finer microlenses than the ee a or ee d along with a steeper parabola of focus to make the image pop in and out of focus more vividly in the viewfinder however the ee s focusing screen is not recommended for slower lenses because its not very bright please note this will not fit the canon eos 5d mark ii