Samsung 40 Inches ES6200

[geekbits]

I have Samsung ES6200 40 Inches. My viewing distance is > 2 times x screen size ( 40 Inches = 2 * 40 ) ie viewing distance is between 80 - 100 inches but getting eye strain / headache. I too observed that when I see the HD with same settings for HD channels, I am not getting eye strain and headache. But when I view the same for SD channles, I am getting eye strain and headache. My settings are as follows

Viewing Distance - between 80 - 100 inches
Contrast - 100
Sharpness - 100 ( Blurred in SD if I go too near..Awesome in HD )
Colour - 45
Brightness - 65
Picture Mode - Standard
Resolution - 1080i


But for viewing HD channels, I don't have any eye strain / headache even if I set to contrast and sharpness as 100 ( Clarity is awesome ). I don't even get a single bit of eye strain / headache. But when I watch the same for SD channels, I am getting the headache / eye strain. I need proper settings and viewing angle for SD channels in order to avoid eye strain / headache.

Samsung Default settings ( below ) for Picture ( Awesome clarity but getting eye strain / headache ). Eyestrain is avoided if I view at 120 inches or more but still getting a slight headache.

Picture - Dynamic
Backlit - 20 (20/20)
Contrast - 100
Brightness - 45
Sharpness - 55
Colour -55
Advanced Picture Mode - Cool



Please do tell me the viewing angle and if my viewing angle is correct, do I need to change the settings ? If so what will be the best settings for SD and HD channels ?


Thanks