Seven is a very important number for the Pentax K-7 – its body has 77 water resistant seals and its new metering system has 77 segments. The latter appears to contribute towards making the K-7 produce more acceptable exposures in a wider range of situations than the K20D, which is quite heavily skewed towards underexposure.
I found that the K-7 is less prone to underexposure than the K20D, and in several instances it correctly exposed the foreground and allowed quite large, bright areas to burn out. Some may argue that it is better to underexpose a scene to preserve the highlights and then brighten the image on the computer, but many photographers prefer to produce images with their main subject correctly exposed in-camera.
That said, part of this test was conducted in overcast conditions and it was no surprise that the K-7 produced underexposed shots when set to its multi-segment metering mode. These conditions are a challenge to most metering systems.
While the K-7 metering system is an improvement on that of the K20D, it doesn’t throw up any major surprises and it is helpful to have an understanding of how a camera’s meter traditionally responds.