Things to Consider when Buying a Monitor

Reprinted from the New York Times
August 22, 2012

Just so you know, when buying a monitor, some marketing genius out there has decided computer monitors aren’t computer monitors anymore. They are “displays.” Raise the curtain and cue the John Williams soundtrack.

Sales gimmickry aside, it is probably accurate to call them displays nowadays. After all, people no longer use them just to visualize what they are typing on their keyboards. They probably also use them to watch movies and television shows, videoconference, edit photos and play video games, not to mention magnify the small screens on their laptops, tablets and smartphones.

Given that consumers are demanding more xfof a display, it might be time to get a new one. The technology has improved remarkably within the last few years, with crisper pictures, faster response times and sleeker, slimmer casing. Moreover, the cost has come down so an exceptional display can be purchased for as little as $200 with higher end, pinch-yourself displays costing about $1,000.

Buying the right monitor depends on what it will be used for and in what location, as well as the acuity of the user’s eyesight and personal taste in terms of saturation of color and contrast.

Because displays are in the eye of the beholder, it doesn’t help to tell you that thinks the Dell UltraSharp U2412M is the best monitor, or that Consumer Reports likes Apple’s 27-inch Cinema Display. Apple, NEC and Dell are often ranked among the highest by product reviewers.

But NEC and Dell still make some models that reviewers consider dogs. And some fault the Apple display for motion blurring and lack of adjustability.

So you really have to make this decision on your own and that means you have to dive into the specs. Don’t glaze over. It’s not really that hard. First, let’s talk about resolution. That is the number of picture elements, or pixels, the manufacturer has crammed into a display. Prevailing wisdom is that more pixels render a sharper picture.

“That’s true but only up to a point,” said Bryan Jones, a retinal neuroscientist and part-time photographer at the University of Utah School of Medicine in Salt Lake City.

The separation between pixels on a screen becomes indistinguishable at about 220 pixels per inch, or ppi. “More than that is overkill,” he said, assuming your eyesight is 20/20 and you are sitting a typical 30 inches from the display. If your vision is less than perfect or you tend to sit farther away from your display, perhaps while watching movies or playing video games, pixel density can be less than half that (90 ppi) before you might notice any degradation in picture quality. If the manufacturer’s specs do not include ppi, and they often don’t, has a handy online calculator.

While ppi is an important consideration, Tom Taylor, who is known as Tsquared and is a Major League Gaming champion, said it was not his primary concern when buying a display. He has six displays in the gaming lair he has created at his house and three standbys in a closet.

“Response time is the first thing I look at,” he said, referring to the time it takes for pixels to respond to the electrical impulses that change their color, which, in aggregate, creates a new image. “Gamers’ hand-eye coordination is twitch reflexes, so more than a 2-millisecond response time is a little delayed for us,” he said.

A superfast response time also reduces so-called ghosting or other motion artifacts in video, which is important if your display will be used to screen movies or edit video.

Also important for moving as well as still images is contrast ratio, which is the ratio between the display’s blackest black and its whitest white. A contrast ratio of 1,000:1 is respectable — 2,000:1 is stellar. Ignore the misleading “dynamic contrast ratio” manufacturers often promote, which can be millions to one. Display experts agree that it is artificially derived and misleading.

Closely related to contrast ratio is black level. “If you want a better movie or gaming experience, you’re going to want to look for a nice low black level,” said Art Marshall, product manager for professional and medical desktop displays at NEC. “When you’re watching ‘The Lord of Rings’ and what’s supposed to be black around the torch light is gray, it takes away from the effect.”

Manufacturers generally don’t volunteer the black level, but reviews on Web sites like Tom’s Hardware and the German site are only too happy to oblige. The industry says pitch black is zero nits, or candelas per square meter (cd/m2), which is nearly impossible to achieve in a display, so look for something less than 1 cd/m2.

Brightness level determines the maximum intensity of the white opposing the black and is especially important if you will be using the display in a very sunny space like maybe a blindingly bright solarium. In that instance you would want about 350 cd/m2 rather than the more typical 250 cd/m2.

Be aware, though, that brightness degrades over time. “The bulbs backlighting displays begin losing their intensity the moment you turn them on,” said David Hirschorn, director of radiology informatics at Staten Island University Hospital, whose job demands he be picky about his displays. Light emitting diode, or LED, backlights are brighter, he said, and tend to last longer than their compact florescent, or CFL, counterparts and generate less heat.

“I’m done with anything that isn’t LED,” said Vijay Mathews, partner and creative director at Winfield & Company, a digital design and development studio in New York, particularly when LED displays also allow for a wider color gamut, which is the range and intensity of colors a display can produce.

It is commonly expressed as a percentage of NTSC, which is a broad color spectrum standard created by the National Television System Committee. The higher the percentage, the richer the color.

Sometimes manufacturers will indicate a display has an “sRGB” color gamut, which means the display is capable of about 75 percent of NTSC. “AdobeRGB” color gamut allows around 92 percent of NTSC. If the specs indicate a color gamut exceeding 100 percent of NTSC, the colors will go beyond what you see in the real world — excellent for anyone who is into psychedelic animation.

But make sure the display has a decent viewing angle (close to 180 degrees), otherwise colors will tend to shift and degrade if you view the screen off center.

Ergonomics are also important. Adjustable height and tilt is essential for reducing eye, neck and back strain. And being able to rotate the screen for both landscape and portrait views can make it easier to work with oddly shaped or elongated documents like blueprints or spreadsheets. Also consider whether the display has a matte or glossy screen. Glossy screens can emphasize contrast, but can also produce an annoying reflective glare.

“I find high-gloss screens infuriating,” Mr. Mathews at Winfield said. “I don’t want to see my face in my work.”

The last thing to consider is the number and kind of connectivity ports. A couple of USB ports may come in handy, as well as ports for DVI, HDMI or display port cables, that will connect with various devices.

Tim Vehling, vice president for product marketing at Silicon Image, a high-definition content distributor, said, “The way to look at a display is more of a productivity station to plug in other devices — phone, camera, Blu-ray player, camcorder — to see what’s on them on a bigger screen.”