Why Interlacing Is Used?

Interlacing provides full vertical detail with the same bandwidth that would be required for a full progressive scan, but with twice the perceived frame rate and refresh rate. To prevent flicker, all analog broadcast television systems used interlacing.

Why was interlacing invented?

The interlace method was developed for TV broadcasting because the allotted bandwidth for TV channels in the 1940s was not sufficient to transmit 60 full frames per second. It was decided that interlacing with 60 half frames was visually better than 30 non-interlaced full frames.

Why is interlacing so bad?

The cons of interlaced scanning are the movement within the frame can cause motion artifacts. This happens when the motion is really quick that it causes noticeable differences in the positions of the fields. An example of this is when you shoot sporting events with really fast motion, many artifacts can be generated.