I am finding it a bit hit and miss getting accurate manaul focus with my camera. I wear glasses for seeing distance, and I have adjusted the diopter on the camera so that what I see is clear in the viewfinder. However, quite often when I think I have something in focus it end up being just a bit out of focus. AF works fine, but I want to be able to selectively focus when required. What is the magnifying eyepiece that I need for the D2X? Would this help, and do you still see the full frame in the viewfinder? Does the diopter adjuster still function with the magnifying eyepiece fitted? Thanks in advance for any info.