1080p24

The Argument for 1080p24 and the upcoming world of 120Hz displays

We can go on and on about video processing (and we will in a future article). On the frontier of video processing are two separate features: 1080p24 and 120Hz displays (typically with inter-frame interpolation).

Hollywood movies are all recorded at 24 frames per second. Since most TVs in the US are built around the 60Hz format, a single movie frame is displayed twice (1/60 * 2 = 1/30), and then the next frame is shown for three cycles (1/60*3 = 1/20). This process repeats. The problem is that while each frame of the movie gets “equal time” in the real movie theater, with the traditional 1080p60 display, every other frame of the movie gets shown for an extra 1/60th of a second in comparison to the frames immediately preceding or following it. This produces an effect known as motion judder in which motion isn’t quite as smooth in a home theater environment running at 1080p60 versus the presentation in the movie theater.

To solve this, a handful of a high-end manufacturers have developed ways around this and this is soon making its way to the standard consumer market. The majority of Blu-ray players support 1080p24 output, and HD DVD players will soon be able to do this as well (LG’s SuperBlu is the only one I know of at the moment; the Toshiba HD-A20 and HD-XA2 are scheduled to receive a firmware update enabling this feature). The trick is the TV. 1080p24 displays are still few and far in-between. Pioneer Elite Plasma screens have had the capability to present DVDs and movies at native 24p by running the display at 72 Hz (24x3).

Is judder a big deal? It’s not as big of a deal as everything else – we’ve lived with motion judder for decades. On the other hand, when you belong to the group of individuals who play PC games and can see the difference beyond 60 frames per second, it’s certainly something to consider. If you already have a 1080p TV that does inverse telecine, I wouldn’t upgrade. However, if you’re in the market for a new HDTV though, it’s certainly something to consider. After all, this article is about a “reference” home theater.