Some material shown on 1080i high - definition channels in the US originates from material shot on older cameras that was only capable of 1440 samples per scanline .
This material is generally quite acceptable to most viewers and is considered high - definition .
Some material shown on 1080i high - definition channels in the US originates from material shot on older cameras that was only capable of 1440 samples per scanline , yet this material is generally quite acceptable to most viewers and is considered high - definition .