There is no truth about this belief.
The picture quality of HDTV is boosted with more pixels in the firm space. A large number of 50 - 63 inch plasma televisions have that type of cell that can fit the numerous pixels needed in order to produce full HDTVs clarity. In past, almost all forty two inch plasmas weren't High defintion television able. So, these days there is scarcely any 42 inch plasma TV that can't generate HDTVs resolution. But, Nowadays, even smaller screens can perform the similar work. The companies which has grounded these TVs are Philips in addition to Sony.
Make aure respecting the fact that HDTV resolution can be showed by a plasma TV which you are keen to obtain. Everybody can check this fact either your plasma is ‘HDTV capable’ just by asking the dealer. Shop it only if he tells it is ‘HDTV compatible and not ‘HDTVA capable HDTV fitted plasma TV suggests that it can easily receive the HDTV signals however would screen them in a reduced resolution.
Be certain that the plasma display is having at least 720 x 1200 or 1024 x 1024 if you are looking for the impression of HDTV in a plasma TV.