Mike,
This is a bit off topic, but......
I use a 5D. It is permanently on a tripod in my line of work. And I *always* use the mirror-up function. (Custom Function 12).
This must be used in conjunction with the self-timer. When it is, on pressing the shutter, the mirror is raised and two seconds later the shutter fires.
This avoids all "mirror slap" and noticeably improves resolution at critical magnifications.
An indispensible feature on this fabulous camera.
If you shoot things that are standing still, you should use it.
Apologies if you already know about this and it's of no use to you anyway!
D.