Originally posted by skyer but how does it does correspond to the K-1's specification where it is said that the K-1 features an 86,000 pixel RGB CCD metering sensor
I can't account for 86k precisely. The data recorded in the EXIF is comprehensive, but hard to figure out.
Specifically, the way the metering segments are recorded in the EXIF doesn't form an easy to read pattern. It would be great, for example, to find a single 3:2, 360x240 data array in the EXIF data, with each data point recording one pixel/ segment, neatly leading to 86400 pixels total. But the data isn't structured that way. Instead we get 5 x [45x30] blocks of data out of Exiftool.
I can literally 'see' the data from those 6750 metering segments in Excel, but I don't know how may pixels were involved in producing each data segment.
We know that as an RGB sensor, we should expect 3 pixels (R/G/B) to provide the data for each measurement. You can see from microscope images of RGB sensors (like the Chipworx image below from the 2k pixel Nikon D600 RGB metering sensor) that such sensors are laid out as striped arrays, with successive columns of red, green, and blue elements:
So in a crude way I might be able to account for 20,250 of the pixels (6750x3) in the Pentax RGB sensor. But without a similar microscopic scan of the Pentax sensor, and a better understanding of how the chip works, I can't precisely verify the 86k specification.