Are LCD Manufacturers Keeping Us in the Dark? - A Comment on Response Times

Choosing between LCD televisions is not an easy thing to do. The technical specifications quoted by manufacturers often cast a veil over the actual performance of any given machine giving the buyer one giant headache when trying to get the best LCD TV for his budget.

Now there are always going to be a few factors that play a big role in the final decision of the consumer including the styling of the LCD TV, the brand and of course the price. But the latest deal swinger that can make or break a sale is that of the LCD response time.

But have manufacturers rendered this measurement useless? The answer should become a little clearer if we look into the details.

So what does the response time of an LCD TV actually mean?

Response time is traditionally defined as the time taken for a pixel to change from black to white and then back to black again. This has historically been the figure quoted for the majority of LCD TVs and computer monitors.

And why does this time matter?

Older generation LCD TVs and some of those made by second tier manufacturers which have slow response times experience a problem with the picture quality when the objects on the screen are moving fast. This issue is known commonly by several names including image lag, blurring, ghosting and the “comet effect”.

It can lead to a rather unsatisfactory viewing experience for what are quite expensive pieces of entertainment equipment.

So how are manufacturers cheating this system?

Well typically an individual pixel will not go from totally off (i.e. black) to totally on (white) but rather along the gray scale. On an LCD TV colours are defined according to the gray scale which basically determines how much light a pixel lets through to the screen.

But when a manufacturer quotes a gray-to-gray figure for the response time things become unclear. What measures of gray have been tested?

Some manufacturers will purposefully quote a gray-to-gray figure defined by themselves (but not revealed) to mask deficiencies in their product. This makes response time an almost impossible thing to be confident about.

What should I do as a consumer?

First tier manufacturers such as Sony, Panasonic, Philips and LG are often more reliable when it comes to quoting response times and will often quote a “typical” time to give you a good idea of the average performance of the machine.

If it is possible try and see the LCD TV in person before you buy. Or if you are looking for the cheapest prices online then seek out product reviews from the retailers’ websites and from respected online consumer magazines.

What can the industry do in general?

To lift this veil and resolve the issue of response times the LCD TV industry should decide upon a standard measurement of the gray-to-gray response time. This standardisation would force the manufacturers to give a clear representation of the true performance of their screens and help the public compare and choose the right LCD TV for them.