Buzzword: What does OLED bring to a tablet?

Samsung recently released two new tablets, the Galaxy Tab S 8.4 and Galaxy Tab S 10.5, both with AMOLED displays. The displays on both were excellent, but so are the non-AMOLED displays on many other tablets, from Samsung and other manufacturers. So just what does AMOLED mean, and what does it offer?

AMOLED is all about providing blacker blacks, better viewing angles, more readability in sunlight, and efficient power use.  The acronym stands for active-matrix organic light-emitting diode. In plain English, that means the pixels on an OLED display use LEDs that emit light at different intensities, rather than using liquid-crystal shutters that block varying amounts of light. The "active matrix" part is a format used on larger displays rather than smaller ones such as those found on cameras.

Our tests showed that the Tab S does indeed provide blacker blacks than many of its competitors, where dark areas are truly black without bleed-through. As a result, the blacks don't look washed out as they do on some other displays, something you'd notice most if you're watching a movie in a darkened room.

Generally, the whites on OLED displays have not been as bright as those with LCDs. The problem with whites occurs because every pixel on an OLED screen is an individual LED light that turns on to different degrees. It's like using a dimmer to control brightness instead of placing a shade over a lamp, which is what non-OLED screens do. That means you're potentially using less power. But when there's a lot of white in a picture, the total current gets limited to prevent overheating. As a result, whites are less bright on OLED than other types of displays. What does that mean to you? With the brightness turned up, pictures with a lot of white won't pop as much as on an LCD with a backlight. Early OLED tablets had this problem to a more severe degree. With the Galaxy Tab S, Samsung has managed to alleviate it a bit.

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The viewing angle on the Galaxy Tab S is extremely wide in portrait and landscape orientations, as it is on other tablets with excellent displays. And, as you'd expect with an OLED screen, readability in sunlight was very good.

Finally, battery life was great at more than 11 hours on the 8.4-inch and the 10.5-inch models.

Do you need an AMOLED display on your tablet? Probably not. Displays on Samsung tablets, for example, have been consistently excellent in our tests. If you want a Samsung model with the very latest technology, you'll be happy with the Tab S. But you can also save quite a bit of money with the Samsung Galaxy Tab Pro 8.4 and 10.1, which also have excellent displays and long battery life.

To learn more, take a look at our latest tablet Ratings.

—Donna Tapellini