Originally posted by stevebrot There are accuracy standards for light measurements, but none that translate directly to appropriate exposure.
Yeah, this is it. Imagine you have a frame that is all equally lit, except for one corner which is much brighter. Or a center that is much darker. Or maybe its a portrait of a woman in a big, white wedding dress. Or its a photo of a big black car. All of these things put the camera into a position where it will make a decision - but not necessarily the decision you want. As a photographer, you are supposed to learn you camera's behaviours (and settings) so that you can make it produce the image that you want. The main point is that there is no objectively correct exposure. People just think there is, because our brain generally adjusts this without our knowledge, except in extreme conditions. Cameras are still too stupid to mimic this perfectly, especially since they have completely different recording devices, lenses, and so on.
I shoot raw, so when I am out, I am often using EV+/- to get what I want. Sure, sometimes I fail. Sometimes I use ETTR technique. Sometimes I just get close enough and adjust in post.
Anyway, I think the K-3 and K-3II have the latest metering technology and the most zones for matrix metering, with the latest predicting algorithms. So its "the best." Even though many people were completely capable getting what they want with previous models, as far back as the first DSLRs (which seem technologically primitive, compared to some of the stuff we see today) and even older SLR cameras, some of which had no metering at all.