Originally posted by shaolen why do pentax bodies always underexpose
This is an historic complaint.* The practical aspects are covered above and the intent is to avoid highlight clipping. This is commonly referred to as ETTR (Expose To The Right). The resultant photos usually look somewhat dull and grim, but you can recover from the mild underexposure in PP. This is preferable to losing the highlight detail to clipping. The situation is not as simple as a consistent 2/3 stop downward bias in that there looks to be a more complicated algorithm at work.** After all, they don't call it multi-point matrix metering for nothing. Jatrax is quite correct that the K-3 seems to do a better job than earlier bodies.
Steve
* IIRC, underexposure was the subject of RiceHigh's initial series of anti-Pentax rants back in the ancient past.
** Gray card readings are generally comparable between the camera and hand-held meters.