View Full Version : LCDs and Vertical Viewing Angle

2011-01-13, 02:30
A year ago (maybe two) I bought a small Toshiba LCD television for the bedroom and have grown increasingly frustrated at how the colors invert (or go black, or whatever the technical term is) when viewing the screen from an angle below horizontal... say, when I'm sitting/reclining on the bed. This little TV was a quickie replacement for an old CRT but I'm wondering if vertical viewing angle is a much-discussed property when people evaluate LCD televisions. Should I assume that this characteristic has improved on the most recent models?

Dorian Gray
2011-01-13, 17:33
Hey drewprops, it was a couple of years ago (http://forums.applenova.com/showthread.php?t=30964). I recommended a cute OLED TV and Robo told you, too late, to get a Sony BRAVIA. Either one would have solved this problem for you. :p

Much like good computer monitors, good small TVs are relatively uncommon these days. Such is the price pressure that almost everyone puts crappy TN panels in their small LCD televisions, and TN panels have poor vertical (and horizontal, but not quite as bad) viewing angles. Your Toshiba has a TN panel (though Toshiba also makes larger TVs with great LCD panels).

With a quick spot of Googling just now, I see that the situation in the US is even worse than on this side of the Atlantic: the small TVs are even cheaper and even crappier, and you have to go to a larger size class (32" seems a sweet spot in the US) to have a decent chance of getting a good LCD panel. The situation was a bit better two years ago (though the prices then were higher, of course).

With more time and energy than I have right now, you might yet find a small but good LCD TV in the US market. You need to look for TVs that use PVA or IPS panels in preference to TN. You might find the panel type mentioned in the marketing materials (e.g. Panasonic's "IPS Alpha"), or you might find oblique references to it, such as boasts about wide viewing angles. Narrow your search by looking at the most expensive TVs of the size that interests you.

On viewing angles (arcs of acceptable quality), I should mention that all types of LCD panel suffer at viewing angles other than perpendicular to the display. The maximum contrast ratio starts falling immediately as you move off centre, the image brightens, darkens, or flips, and colours lose their vividness. So if you want to experience the full richness of the display, you need to view it perpendicularly (from infinity, so the corners are also perpendicular! :D). The manufacturers don't like describing the viewing angle as zero degrees, so they choose a cut-off point that makes the display sound better. Absurdly, the industry commonly sets the acceptable limit at a contrast ratio of 10:1 or 5:1. As you might imagine, a picture doesn't look great with a max contrast ratio of just 5:1. (Good cinemas have contrast ratios as high as 500:1, or sometimes even beyond.)

This explains why you commonly see viewing angles described as 160, 170, or even 178 degrees. That's the arc within which the display can achieve a contrast ratio greater than or equal to 5:1 or 10:1, depending on which cut-off point the manufacturer feels like using. Very occasionally a manufacturer will actually tell you the value they're using to describe the viewing angle (I fear this happens only when the marketing people don't understand how these numbers incriminate them). For example, have a look at the "Specs" tab for this display (http://www.viewsoniceurope.com/uk/products/desktop-monitors/lcd/value-series/va1916w.htm).

These viewing angles are obviously useless for determining the acceptable viewing angles, where acceptable means better than ten-year-old newspaper print, but they're useful in another sense: only PVA and IPS panels can achieve a contrast ratio of 10:1 over an arc of 178 degrees. TN panels, on the other hand, cannot muster even a 5:1 contrast ratio at 89 degrees off perpendicular (i.e. a 178-degree viewing angle).

In short, look for a TV with a viewing angle of 178 degrees. It won't provide a useful viewing arc of 178 degrees, but it will deliver a vastly better picture at 30 degrees off-centre than a TV offering a 170-degree viewing angle. And that's especially true in the vertical direction.

If it's any use, in the UK there are at least two interesting 19-inch LCD TVs: the Sony BRAVIA KDL-19BX200 (PVA panel) and the Panasonic VIERA TX-L19D28 (http://www.pocket-lint.com/review/5160/panasonic-tx-l19d28-television-review) (IPS panel). The Panny in particular offers truly outstanding picture quality. They both have dreadful sound quality, as in boggle-the-mind bad. But good images. I didn't find something similar in the American market when Googling (above), but that doesn't mean it doesn't exist.

2011-01-13, 20:45
Thank You! Thank You! Thank You! Thank You! Thank You! Thank You! Thank You! Thank You! Thank You! Thank You! Thank You! Thank You! Thank You!

SO helpful!!
A little research shows that the KDL-22EX308 that I bought my folks last summer has a horizontal AND vertical viewing angle of 176º, which is close enough to 178º as to never mind. If I can talk them into getting a Sony Google TV I might get the KDL as a replacement! :D


2011-01-13, 20:58
Ewww, Google TV is so half-baked still...

2011-01-13, 21:05
I'm a sucker for weird remote controls?

2011-01-13, 21:48
say, when I'm sitting/reclining on the bed.

You should stop watching TV when you are having sex. Problem solved. :p

2011-01-13, 21:50
You should stop watching TV when you are having sex. Problem solved. :p