Background

• A TV’s refresh rate refers to the number of times that the TV displays an image on the screen per second. A movie is recorded at 24 frames per second, which is converted to 30 frames per second when made available for a home video. According to a 2011 "PC Magazine" article, the source footage recorded on a Blu-ray disc is never greater than 60 Hz, and a TV cannot add more detail beyond what is in the source footage -- the content of a Blu-ray disc, for instance. A Blu-ray movie is a 1,920-by-1,080 resolution, or 1080p, picture at 30 Hz.
  
  

Interlacing

• The difference between a 60 Hz LCD TV and a 120 Hz set is the way that each TV performs the interlacing process. A 60 Hz TV combines and shuffles the 30 frames per second into 60 frames per second, essentially spreading out the picture frames so that it matches the refresh rate of the TV. A 120 Hz TV introduces more data between each frame to create additional frames to reach the 120 fps of the TV. However, according to "PC Magazine," a 120 Hz TV is only using the original data from the source footage, rather than adding new data that could make it appear to the viewer as though there is more detail in the picture compared to a 60 Hz TV.
  
  

Motion Blur

• Film-based material typically includes some “judder,” which is a kind of stuttering effect that occurs when the camera is slowly panning, or when a scene is filmed with a hand-held camera. This means that an LCD TV with a faster refresh rate appears to the viewer to have less motion blur and an overall smoother image. In addition, TVs with higher refresh rates have less “ghosting,” which is when there is an afterimage left over when the screen changes.
  
  

Considerations

• Ultimately, a decision over whether to purchase a TV with a 60 Hz refresh rate and one with 120 Hz comes down to personal tastes. Many viewers prefer less juddering with a picture and opt for a 120 Hz TV. On the other hand, according to CNET, many viewers prefer the juddering effect because it looks like film. Removing the judder makes a picture look more like video.