Ok so I am stilllearning butwhen using one of the calibration discs should you do it in as dark a room as possible even if most of your viewing is with at least some light on and sometimes with full room lighting? Or is this a situation where you should do it both ways under different imputs and change imputs on the TV for different times of day. I have a Panasonic 850u if it makes any difference.

You always calibrate to your viewing enviornment. If you primarily watch your display with ambient light, calibrate your black levels to that ambient light level. If you have varying ambient light levels, and the display has the ability to save multiple settings, set up a day and night preset.

Thanks