The DVD format offers approximately 500 lines of resolution, the maximum our television system, NTSC, is capable of showing. These signals will require a new digital-ready TV that is able to display them, or a converter box that can reformat the signals for standard TV sets. The comb filter is one of the critical features of any TV set. How cleanly those signals are separated is the job of the comb filter. When the images are displayed on the screen, the lines between colors should be sharp and clean, not blurry as if drawn with a crayon, or jagged with blocky edges.
Notch filters are the crudest and are found on inexpensive, entry-level TV sets.
Sharpness A Sharpness control can often have the opposite effect. Check the setting on your TV - it's usually at the midpoint. Adjust the control up and down. Watch the edges of lettering and lines. Turn the Sharpness down until any white halos on lines or lettering are lessened or disappear.