I have a Toyo 3.6X loupe and a Schneider 4X loupe. I am nearsighted, and even wi th glasses on under the darkcloth (a hassle) I have trouble with fine focussing of distant objects with both of these loupes. I am thinking of using an 8X loupe . Canon makes one with a wide (30mm) opening. The Schneider 8X has a 15mm eyepie ce. I use a Canham DLC 4x5. Does anyone use an 8X ??? Any advice or comments ?