Wow that makes soooo much more sense now. I don't know why it was so hard for me to grasp that DOF is a subjective quality of a photo, which is highly dependent upon the human eye.
Welcome to the club :-> ... my guess is that often we talk about "hard" nerd/tech stuff which is a nice distraction and sometimes very helpful if you need specific advice. But over all that, the elephant in the room gets overlooked, meaning that so much about photography is "soft", subjective and relative. The only time this regularly surfaces is if someone is cornered in an argument and states something beyond the original point like "Well, but a good photog can shoot great images with a 10d and tech details don't matter anyway."
Good point. And I assume somewhere in this thread, someone has mentioned how the depth of field always looks deeper via your eye through the viewfinder, than what the image sensor sees? There's probably a name for this phenomenon. (It's at least partly due to the fact that your eye has its own iris, along with the eye's "imager" not being the same size as the camera's...and probably a host of other factors.) I didn't notice this as much before I started using sensors larger than aps-c. Oddly enough the first time I really noticed it was with my 58mm f/1.4 on the 1D4, a 1.3x crop camera. This is why it's almost impossible to manually focus a fast aperture lens accurately...especially if you're just using the standard focusing screen, and the distances are closer than 10 feet or so.
However, none of this brilliance you all are imparting, is getting the lens I want, designed. 60-110mm f/0.7 zoom w/4 stop multi-axis IS, painted metallic pearl white...with 14,000 months/ no interest...one day only sale! (The day they're only open half the day...and no web orders taken during closed hours...etc...)