[NeverSatisfied]

"That's not how it works. EV+ increases the exposure to allow more light. EV- lets less light in. When you are shooting snow, you dial in EV+ to brighten the snow to avoid the snow being gray. When shooting black, you dial in EV- to darken the item to avoid the black being gray."
OK, that was my understanding. Thanks!

Lowell, your reference to using the green button in changing light: is that -along with- using EV comp? I use M mode mostly, and use the green button a lot. So it sounds like you'd quickly get the "proper" exposure with the green button, but meanwhile the EV comp setting you'd already chosen remains constant, the result would be the desired amount of over- or under-exposure. Correct?

Glad you said that about using TCs. I remember using the 1.4 TC on my 50-135, and having to use EV comp to get the right exposure.

I can almost see EV comp being more useful in M mode, than in Av or Tv- after all, as far as the latter two modes are concerned (and as I just learned last night), all the camera is going to do with your EV setting is adjust the opposite value accordingly. At least in M you would still have complete control over your shutter and aperture settings. Or am I still missing something?

Interesting point about using older manual lenses, good to know.