Originally posted by Rupert
Back again.....Can someone explain this to me? What is a photometric sensor and how does this relate to better AF? Try to explain it in terms that would be understandable to a squirrel brain...if possible? Not that I have a squirrel brain, Otis constantly reminds me I am not that advanced, but I am pretty close!
Regards & Thanks in advance!

The photometric sensor is the sensor that measures illumination to decide on exposure. Being colour-sensitive means that it "sees" the colours and not only the luminance (i.e. in black and white) like past systems.
As already explained

in answer #10 to this thread:
Originally posted by Mistral75
(...) Being colour-sensitive, the tracking system will avoid to change target when something else suddenly crosses the detection area of the AF point locked on the target.
You are photographing a soccer match. Your son is dressed in blue. You are following him, shutter half pressed, waiting for the best moment to shoot. Suddenly a guy in red enters in your framework and his trajectory crosses that of your son. With a conventional system there is a chance that the tracking shifts from you son to the other guy and your son gets blurred when you press the shutter. With the K-3 system, there is no such risk.