Why are pictures on lcd tv's grainy?

Question

it is crystal clear only when we watch DVD's or some specific channels but for most channels, the lcd goes grainy and pixellates. why is this so? and why doesn't HD appear like that

Answer 1

Its not an issue with the television.  It is the source material that is grainy.  The channel that is standard definition is scaled to fit the larger screen of the lcd tv.  It simply doesn't have the data to fill that screen properly.  HD doesn't appear like that because by definition it is supposed to look clearer.

Answer 2

weather?

Answer 3

Sounds like you need a new aerial or an aerial booster if your in an area of bad reception.