I where glasses and would like to know which loupe is best for focusing on groun d glass. Currently, I own a Schneider 10X loupe but have found it's inability t o lock its rotating diopter after focusing it to the ground glass to be problema tic (i.e., it's easy to get it out of focus with respect to the ground glass). Ideally, I would like a loupe that would allow you to lock its focus and perhaps have some sort of eye cup that would aid in keeping the "exact" eye to loupe di stance you used to focus it on the ground glass. I noticed on my last trip that very little up and down eye movement (i.e., varying the distance of the eye fro m the loupe) makes a huge difference in what appears focused on the ground glass . Are there any good loupes out there that perhaps come close to my dream of th e perfect focusing aid?

Thanks in advance,

...Wade...