SteveR wrote:
That is the problem of shooting completely in manual. You must check your meter before taking the shot. When in a hurry, either let your ISO float, or choose shutter or aperture priority. Always, however, be cognizent of what each leg of the exposure triangle is before shooting so you're not surprised with the outcome. If you're in too much of a hurry just shoot on P.
I shoot mostly hurried, unplanned snapshots so I use Program mode. It also allows me to dial in a specific aperture or shutter speed or ISO if I happen to slow down a bit.