When calibrating the picture on your HD TV, the first thing to do is to trawl through all the various menus looking for anything that advertises itself as an ‘enhancement’. These are usually artificial filters and tweaks that will have a negative impact on a properly set up TV picture, so switch them off before you do anything.
Black levels are next to address. Bring down the brightness until black is precisely that, rather than grey. Having done this, you need to find the point at which everything else is most bright but with black still being black. If your set is on a TV wall mount, you can position it to avoid any disruption caused by other light sources.