M lens on K20D..bracket, meter?

[janosh]

....I'm finding that bracketing with M lens is important in a rapidly changing situation, when individual green buttoning isn't possible: a quick sequence of 3 brackets will give one or two good exposures...another one or two of the three will be bad.

In harsh sunlight, either the "normal" or the "under" shot, or even both, will be fine... but odds aren't nearly as good if I gamble it all on one push of the green button...again, this is for rapidly changing events, not for carefully composed individual images.