i'm not sure what it is but most of the shots i take with mkii are underexposed. i always shoot M and never had an issue with any of my previous canon bodies. i've had the 20d, 30d, 40d, 50d, 5d. if i set for iso, say iso1600 for indoors, and F5.6, and shutter, doesn't matter.....the meter is always in the middle, set for proper exposure...it comes out dark! i then set to full auto to see what the cam would select. it chooses iso 800....half as much for indoors! the F is the same, and shutter a little different, and the shot looks great. i don't get it. with any of my other bodies i have always started with iso, 100 usually outside, and 800 to 1000 indoors, then Fstop based on DOF and shutter accordingly. this is how i have done it for years. this mkii is just not cooperating. bottom line..... regardless of settings, the meter is showing correct exposure but it's underexposed. maybe i need to jack the exp. comp setting or something, but i never had to do that before.