first use the HDMI of the rear of the TV, not the one from the side, only with the rear HDMI connector can you reach the native resolution of the TV, and deactivate the autodetection of the TV from the PS3 menu.
colour tone Normal
Black Adjust Medium
Dynamic Contrast Off
Edge enhancment On
Colour Space Large
Pc Home CInema ON
and select resolution of 1360x768 from the PS3 menu (this resolution only appera when you use the HDMI from the rear and you deactivate the autodetection mode in the PS3.
It's a plasma 50 inch tv, what would be best for things like gaming on the ps3