Truly Hd?

[timbo]

Am inquiring that when you select an HD channel, and it first comes on the format changes to 1080i....of course. Does this verify that it is TRULY a HI- DEF signal? Just seems that even though the format says 1080i the picture does NOT seem to be high def. Is it my eyes or is this possible?
I know there is a big difference in broadcasts BUT???
Any info would be appreciated.
Thanks.