With the Samsung LN40A550's Dynamic Contrast set to LOW and Backlight set to 5, Contrast 85, Brightness 45 my picture (in my opinion) is VERY GOOD.
QUESTION: Does using Dynamic Contrast alter the Backlight , Contrast and Brightness settings (mentioned above) in any way since the picture quality becomes noticeably better when Dynamic Contrast is turned on even to the LOW setting?
From playing with my own set, it appears that dynamic contrast changes the brightness and contrast levels, but not the backlight (you can put the energy saving setting to auto for that).
I actually find that I have to lower contrast (to prevent bright scenes from getting too bright) and increase brightness (to ensure all the shadow detail is still visible) if I have dynamic contrast enabled.
My Energy Saving is set to Auto (the default setting). Perhaps the Auto setting compensates for adjusting the overall picture. As a matter of fact all other settings other than those mentioned were left to their default settings. Picture Mode is on the default setting of Standard.