How About Color, Contrast and Brightness?

If you’ve been following our posts, you will know that CLEVR is a great acronym to remember when designing digital signage. CLEVR stands for Conspicuity, Legibility, Visibility and Readability – sound principles for those who design content for electronic digital signage. As we learned, these factors are weighted differently according to the application, whether it is a textbook, or a digital print sign, or dynamic signage.

We now want to tackle something that is less the purview of the content designer, and more the responsibility of the display specifier. When it comes to Color, Contrast, and Brightness, you should aim high – as in high contrast, high resolution, and great color rendering. What does this mean for your screens? Are there general rules to follow?  We have been following the plasma / LCD debate for years. One thing for certain is, there is no one right answer. We can, however, give you a decision tree to aid in your selection of screen type, and other features! Follow along here:

Plasma televisions were the first to really change the landscape of modern televisions. Providing large screens at depths fewer than 5 inches, they are easily hung on walls. Liquid Crystal Display (LCD) televisions operate by placing a bulb in the TV that generates light. The light is then passed through millions of red, green or blue liquid crystals where an electric current is applied to turn the colors on and off providing the correct color on the screen.

When comparing Plasma TVs vs LCD TVs we first see two advantages that Plasma TVs have over LCD. The biggest advantage is the size of the television. Plasma televisions can be well over 50 inches, currently as large as 103 inches. LCD TVs are normally less than 50 inches.

Additionally, Plasma should provide a slightly better viewing angle of about 90 degrees compared to the an LCD of about 60 degrees. If you have a wide room that requires viewing the television from areas that are not centered in front of the TV, either of these options will work.

LCD televisions have one advantage over Plasma displays — they are bright, making them an excellent choice for areas where you cannot limit the lighting. The more expensive LCD televisions now have very good response times that are comparable to the other technologies. However the lower end LCD televisions do not. Look for response times below 12 milliseconds with the better TVs around 6-8 milliseconds. Anything higher then 12 milliseconds, you may want to think twice if you are going to watch action video.

Plasmas can be susceptible to the “Burn In” effect. The Burn in effect is what happens when an outline of an image remains on the screen even after the image is gone. This can happen when you have the same shape on a screen for long periods of time. Screens that display the same thing often like stock tickers can cause this. In most cases this will not impact users. And some of the new Plasma televisions have what is called white wash to clear the Burn In, but using this can decrease the life of the Plasma. Today, plasma screens can offer extremely long life – in commercial units – and non-glare surfaces. LobbyPOP professionals offer these advanced features in the units they sell.

So, now why haven’t we yet discussed brightness and color, and contrast (difference between the darkest dark and lightest white), clarity (clean lines, not jagged, around images), etc. Reason for this omission is that the difference in these areas depends on the price and manufacturer of the television, more than on the display technology. Both plasma and LCD perform well in these areas, though you will find the high-end qualities at a better price in the plasma product line – especially when it comes to contrast ratios. Bottom line is that both technologies make for excellent televisions.

There are some differences, which may lead you to one or the other for client digital signage locations, and the Plasma verses LCD decision diagram below should help with those differences.

Plasma vs LCD for Digital Signage - LobbyPOP Blog
Decision Tree for Dynamic Signage Display Selection