Vizio OLED H1 TV Review
"21:9" ("twenty-one by nine") is a consumer electronics (CE) marketing term to describe the ultrawide aspect ratio of 64:27 (2.370:1), designed to show films recorded in CinemaScope and equivalent modern anamorphic formats. The main benefit of this screen aspect ratio, compared to the more common 16:9, is the absence of the black bars at the top and bottom of the screen when viewing content in this format, and a constant display height when displaying other content with a lesser aspect ratio.
The 64:27 aspect ratio of "21:9" is an extension of the existing video aspect ratios 4:3 (SDTV) and 16:9 (HDTV), as it is the third power of 4:3, where 16:9 of traditional HDTV is 4:3 squared. This allows electronic scalers and optical anamorphic lenses to use an easily implementable 4:3 (1.33:1) scaling factor.
The term "21:9" was chosen as a marketing term, first used by Philips in January 2009. Due to its common denominator, 21:9 is more relatable to 16:9, the aspect ratio of regular HDTVs, rather than the correct 64:27 or 21:9. If it actually were 21:9 (2.33:1), the fraction could also be expressed in the reduced form as 7:3, relating to the 4:3 of standard-definition TVs.
It is still prevalent in projection systems, using anamorphic lenses, and supported by a number of consumer electronics devices, including Blu-ray players and video scalers.
It is also used in computer monitors, where the term "21:9" can represent aspect ratios of 43:18 and 12:5 in addition to 64:27. The wider screen provides advantages in multitasking as well as a more immersive gaming experience.
- "Cinematic Viewing Experience". Archived from the original on 2009-01-18. Retrieved 2019-03-13.
- Demers, Cedric; Azzabi, Mehdi (15 June 2017). "What is the Aspect Ratio?". Rtings.com. Retrieved 2019-02-02.
- Simmons, Adam (14 April 2016). "The 21:9 (2560 x 1080) Experience". PCMonitors.info. Retrieved 2019-02-02.