Originally posted by Mr Spocko Setting to tungten did not in my case make any significant difference..if there is one it's only very minor. In normal lighting I had no issues with AF at all. Just if you shoot a lot in this type of artificial light you'll get quite frustrated. In Europe this lighting is very very common indoors. I suspect the AF module was flawed and not field tested properly. I'm still a bit shocked that they did not address this with a new AF sensor.
I guess results in setting to tungsten WB depends on what you are shooting and settings. My not-so-scientific tests show improvement. But I have not really pixel peeped in real world situations. In cases I'm under tungsten light, I usually use live view. And that's because in most cases, it's just casual shooting :-).
If I remember correctly, the tungsten light causes or is seen as CA (or enhances it) by the sensor, hence they added the correction(?) lens in the K-30 AF module. I think this was suggested by someone who really knew what he was talking about. Not sure if it was Falk or someone else. (These discusssions are a year old, I cannot remember exactly).
So maybe did not need a new sensor, just fix the current one.