Andy Clough:
As for Perfect Natural Motion, this is a motion compensation feature that interpolates and adds frames to low frame rate material - i.e. 24fps Blu-ray movies etc. As much of TV, and particularly sport, isshot at 50fps you can turn this feature off for Sky or Freeview.
With regards to sharpness, noise reduction, Mpeg artifact reduction, Colour enhancement: these are all features for improving issues withina picture, where the viewer isn't satisfied. So, if you're not experiencing poor sharpness, washed colours or noise in the picture,they can generally be set to minimum or switched off.
And if the viewer would like an easy way to judge the impact of the overall picture quality processing, they can quickly compare by setting it to the minimum level by selecting cinema mode from the smart settings menu."
I have to disagree with your comment about blurays Andy. Blurays may 'only' be 24fps, but theyre in true progressive. Normal dvds and broadcasts etc are in interlaced which means that it displays half the picture in one frame then the NEXT half of the next frame (2 different frames with 2 different pictures). Its true that motion processing tends to work better on blurays but thats because theyre one whole frame after another with no problems. Interlaced material has the problem of 'deinterlacing' which isnt just fitting each half together, its the fact that the material is converted to work at 50Hz (2:2 and 3:2 cadence depending on what the original material was and what framerate it runs at). Because most motion (probably all actually) processing struggles with these then its usually best to leave them turned off
Sharpness should be an exact setting (Possibly 2, one for HD and one for SD deoending on the scaler used etc)