How They Work

“LED TVs Vs LCD (Cont’d)” As seen in the previous article, the main advantage of Local dimming LED TV technology has both contrast and black levels; and the other is that, Some recent LCD TVs use Edge Lit LED. With white LED backlights the difference between the two technologies isnt very significant, but with RGB coloured lights or a colour wheel to affect the backlight colour the LED TVs have an advantage in displaying realistic colour. Viewing angles are another aspect; the answers to the question will change frequently. What seems to have the greatest impact now on the viewing angle is the quality of the clear glass panel on the front of either LCDs or LED TVs. The thicker and higher quality this glass panel is, the better the viewing angle and somewhat adversely the worse the glare. Anti-glare technologies do prevent glare but they constrain picture depth and viewing angles. Lately, some LCD TVs come with very good viewing angles and picture depth though this was never previously the case. There are many very expensive thin edge lit LED TVs with poor viewing angles showing contrast and black level degradation at a mere 30 degrees off centre. Local dimming LED TVs will naturally perform better with the light coming from directly behind the screen. The big variable in all 3 is the quality of the front glass panel which adds depth, good viewing angles and glare. Anti-glare screens will always have less depth and poorer viewing angles. That said and done, one must take extra care where shopping around of an LCD or LED TV set. Always bear in mind the picture quality, viewing angle as well as the glare or anti-glare factor. There lots of very cheap LCD cum LED sets that could end up disappointing you. Displaying fast moving video is a function of the response time and refresh time in LCD & LED televisions. The type of backlighting in the TV has no effect on the reproduction of fast moving video. You will want to compare response times and refresh rates when making a purchase decision. The new 120Hz, 240Hz, and 480Hz rate features all act about the same in our experience depending more on the manufacturer than the stated Hz rate in effectiveness. The main difference is unrelated to the technology employed and more dependent upon whether or not the TV has a gaming mode that cuts down on the amount of picture processing in the TV. Without the game mode there can be significant input lag with the TV processing not able to keep up with the speed of the game. One slight advantage that LED TVs might have here is that LED TVs have higher feature sets due to their higher costs and therefore will more often include the Game mode. As a result, the pricing of the LED and LCD TV sets will greatly vary according to the technology and quality of the sets. Taking a similar set e.g SONY, LG or SAMSUNG, you could easily notice the difference in pricing based on the technology employed. Of course, this will vary with the quality of picture, e.g. viewing angle, gaming or no gaming etc. One thing that is for sure is that, both LCD and LED employ the Digital TV feature. eddie@afrowebs.com