Talk:21:9 aspect ratio

From Wikipedia, the free encyclopedia
Jump to: navigation, search


It's a common misconception that the aspect ratio of a TV is the same as the ratio of horizontal:vertical pixels. However, TV pixels aren't square. The display itself (in terms of its physical width and height) really does have the advertised 21:9 aspect ratio. Note that this is different to computer monitors, which do have square pixels so the physical aspect ratio is the same as the pixel ratio. — Preceding unsigned comment added by (talk) 20:29, 11 December 2011 (UTC)

In the case of the 2560x1080 panels, the pixel aspect ratio is square, and the panel has a picture aspect ratio of 64:27. Christian Wolff (talk) 17:35, 2 March 2015 (UTC)

Should probably mention the fact that the TV is discontinued, as well as the fact that the TV doesn't support inputs at its native resolution, making connecting a PC to it entirely pointless. — Preceding unsigned comment added by (talk) 11:27, 16 September 2012 (UTC)

Choice of 64:27 aspect ratio[edit]

The 64:27 aspect ratio is the logical extension of the existing video aspect ratios 4:3 and 16:9, as it is the third power of 4:3, where 16:9 of traditional HDTV is 4:3 squared. This allows electronic scalers to use an easily implementable 4:3 (1.33:1) scaling factor.

I don't see how this is true. Since the main point of 64:27 (a.k.a. 21:9) TV is constant picture height, using 4:3 scaling factor is only good for 2.39:1 films (1920 × 804 px actual picture area), though that will still make the picture height 8 pixels less than screen height (1080 px) when scaled up. For 2.35 (1920 × 817 px) and 1.85 (1920 × 1038 px) films a different scaling factor is needed (and a fractional one at that) otherwise their picture height will overshoot the screen's height. 1nktr4p (talk) 01:51, 6 December 2014 (UTC)

You don't scale in both directions, only horizontally. The broadcaster always transmits in 1440x1080. For 4:3 content no scaling; for 16:9 content scale once by 4/3 giving 1920x1080; for 64:27 (aka 21/9) content scale twice by 4/3 giving 2560x1080. (talk) 04:32, 31 December 2014 (UTC)
This is incorrect. Even if the broadcaster is chosing to encode the video with a 1440x1080 resolution, to reduce bandwidth, the encoded picture is still fixed at an aspect ratio of 16:9. 4:3 content would still be encoded with black pillarbox bars on the sides, and take up 1080x1080 pixel in the center of the 1440x1080 signal. Also, small black bars (less than 10 or 20 lines) are usually ignored. Just as 1.85:1 movies on a 16:9 TV, where the black bars of 21 lines remain in the picture on most TVs, or are reduced or removed by the overscan crop of the TV. This fact allows for 21:9 displays to apply a fixed crop of 1920x810 and a fixed scale factor of 4:3, for any 2.35:1, 2.39:1 or 2.37:1 content. Christian Wolff (talk) 17:35, 2 March 2015 (UTC)

TVs only?[edit]

There is(was) a S300(Iconia Smart) smartphone by Acer which had 21:9 screen. "4.8" HXGA TFT", "4.8" 1024x480" and "21:9 MULTITOUCH LCD" mentoned on the box. Not gonna edit anything (too new to do that imo), but can provide photos of the box and phone itself, if anyone is interested.Mondrial (talk) 16:53, 15 March 2016 (UTC)