How to Calibrate Your Monitor
Oct 28, 2011 | ITNews.com
If you're an avid photographer, you've probably shot tons of photos, investing a large chunk of your time and disposable income in a digital SLR camera. And you’ve spent even more time learning the ins and outs of photography, including lighting, composition, and image editing. So why don’t your photos look better than they do?
Maybe it’s your monitor.
Why Should You Calibrate?
Calibrating your PC display is an important step, for one simple reason: You want the colors and black levels to look as accurate as possible. The most obvious benefit of proper calibration is that it ensures the best results when you're editing or viewing photographs. But accurate colors and black levels also make videos and games look better on your monitor--you’ll be viewing content in the way the content's creators intended.
In this article, I'll talk about how you can use Windows 7’s built-in tools to perform a quick calibration. Then I’ll mention a website or two that can aid in calibrating your display. Finally I’ll discuss a low-cost hardware tool, to give you a feel for how you might use something similar to calibrate your monitor.
Consider the Monitor's Capabilities
Before diving into the minutiae of monitor calibration, I'll talk a bit about displays themselves. At first blush, it’s a great time to be a computer user: Big, bright displays with very fast response times cost a couple hundred dollars. What’s not to like?
Well, they may not be very good. Most low-cost LCD screens use TN (twisted nematic) technology. The response time of TN displays can be fast, but most of these monitors are limited to a color depth of 6 bits per pixel. With three pixels representing the red, green, and blue primary colors, this means the number of simultaneous colors on screen is limited to 262,144. Such displays simulate higher color depths via dithering--a process that digitally simulates greater color depths than are really available. That’s why, if you’re looking at an image with finely shaded color gradations, you may see color banding.
You really want a monitor with a color resolution of 8 bits per pixel, since such a display is capable of showing over 16 million simultaneous colors. A few monitors capable of 10 bits per pixel are shipping now, too.
Most of the higher-end displays that support 8 bits per pixel use either a version of IPS (in-plane switching) or some flavor of PVA (patterned vertical alignment). Both technologies are more costly to manufacture, but you can find relatively good, 24-inch IPS-based displays for around $400. The point isn’t to focus on the LCD tech as much as it is to pay attention to better color depth.
Set the Color Gamut
You often see higher-end monitors touted as having wide color gamuts. Although many models let you set your color gamut of choice in their on-screen menus (aka on-screen displays), some high-end 30-inch monitors have no built-in video-processing chip. If that's the case with your monitor, you need to use Windows' display controls to adjust the color gamut. I’ll give you a closer look at the advanced Windows display control panels shortly.
A good rule of thumb is to set your monitor's color gamut to match your target output device. If you’re mostly editing photos that go up on websites, good old sRGB works just fine, even though it’s “only” 78 percent of the NTSC color gamut. If your printer is the target device, you may want to set a higher color gamut, depending on the printer model. But then you have to worry about the color settings on the printer. Calibrating for printer output is a whole other topic that requires its own article.
I want to focus on monitor calibration for everyday use and for uploading photos to the Web. I’ll mention calibrating for video in passing, but the assumption is that you'll view the video on your monitor, rather than burning it to a Blu-ray Disc for playback on an HDTV.
Understand the Monitor Settings
Before diving into the act of calibration, it’s worth discussing monitor settings. The display I’ll be using as an example is the HP ZR30w. This monitor lacks a built-in video processor, so the only physical adjustment you can make on such a model is the brightness of the backlight. You handle any other adjustment through the graphics card's software controls. AMD, Nvidia, and Intel all offer software controls to tweak color balance, contrast, and so on.
Most monitors do have built-in video processors, and give you a host of physical controls for the display. This can lead to adjustment confusion: Do you use the monitor controls for brightness, contrast, gamma, color, and so on? Or do you use the graphics card control panel?
My personal preference is to avoid relying on the monitor controls. I prefer to put the monitor at some standard setting; if, for instance, it has a default setting for D6500 (which means a color temperature of 6500 kelvins), I use that. I turn the brightness and contrast down fairly low, as well; if I have the option, I’ll set the brightness level to roughly 200 cd/m2 (you may see this setting reported on some sites as 200 nits, though the units aren’t exactly the same).
If you’re working with an automated calibration tool, such as the Spyder 3 Express I’ll use as an example later, typically it will load all the calibration data into the graphics card instead of the monitor. Some professional calibration tools coupled with certain professional-grade displays can actually adjust the LCD panel itself, but those combinations are often very pricey--though they do ensure very accurate calibration.
If a monitor doesn't offer a specific color temperature number, I usually use the 'warm' setting. I also alter the preset to something like 'photographs' or 'video' if those presets exist. Beyond that, I rely on the graphics card control panel.
Since we're trying to keep it simple, let’s look at how you can easily make changes without getting too intimate with either the graphics control panel or the monitor display controls.
Set Up Windows 7 Color Calibration
First, bring up the Windows Screen Resolution control panel by right-clicking on the desktop and selecting Screen resolution.
Click the Advanced settings link. You should see the advanced display control panel. Click the tab labeled Color Management.
Now click the single, large Color Management button.
Before you click the big Calibrate display button, it’s worthwhile to take a little time and examine this panel more closely.
In this example, since I have an HP ZR30w LCD screen without a built-in video processor, I need to use the graphics card control panels for adjusting color. Also note that I’ve set the viewing conditions profile to 'WCS profile for sRGB viewing conditions'. This selection uses the ZR30w profile--installed from the driver CD-ROM packaged with the monitor--rather than the system default.
Now that you have your gamut settings in place, it’s time to calibrate the display.
Next page: Calibrating a monitor in Windows 7
Calibrate With Windows 7 Tools
The tools built into Windows 7 for monitor calibration are simpler versions of those that shipped with the original Windows Media Center. You can use them to adjust the contrast, brightness, color balance, and gray levels. Since the HP ZR30w I calibrated doesn’t offer on-screen controls, I need to use my graphics card control panel to adjust contrast (the display has a brightness control).
Above is the AMD graphics control panel for adjusting color, brightness, and other calibration settings. Nvidia and Intel offer similar panels with their graphics hardware.
When you start up Windows 7 calibration, you get a simple gray screen, with a 'Next' button and a link to a help file. All you need to do is walk through the steps, reading the instructions as you go along. What you see with each step is a basic instruction screen, with examples of good and bad images. You want to try to replicate the 'good' image as closely as possible.
First up are your gamma settings.
Then you move on to brightness.
After brightness comes contrast.
The last actual calibration setting is color balance, which turns out to be more of a grayscale adjustment.
Once you finish calibrating, Windows (if you wish) will walk you through ClearType setup, an optional antialiasing technique that makes on-screen text easier to read.
Next page: Some useful tools
Web Tools to Try
Web-based calibration tools are also available, though most of them require even more manual adjustment than the Windows method does. Websites such as Display Calibration let you work with test patterns and examples of what a correct image should look like; to calibrate from them, however, you’ll need to become intimately familiar with either your monitor controls or your graphics card control panel.
Whether you use the Windows method or Web-based tools, the process is manual and requires heavy use of your own eyes. Of course, the problem with eyes is that they vary in capability--and if you’re even slightly color blind, visually calibrating your display becomes difficult.
Thankfully a host of automated calibration tools exist, ranging in cost from $80 to thousands of dollars. Certainly, if you’re a professional photographer or videographer, you’ll spend what you need to get the tools necessary for precise calibration. Most people, though, can get by with less expensive tools such as Datacolor’s Spyder 3 Express.
Buy an Automated Tool for Simple Calibration
The Spyder 3 Express costs from $80 to $100, and fully automates the calibration task. It's just one example of a simpler tool; if you want more precision and a higher level of control, you need to invest more money.
For now, ensure that your monitor is warmed up (leave it running for at least 30 minutes) and that you have installed the latest drivers for your graphics card.
Using the Spyder 3 is quite easy. First, install the calibration software (check the Datacolor website for the most recent version). Launch the software, and let it walk you through setup and calibration. Connect the puck to a USB port, and hang the puck from the top of your display, aligning the puck with the outline that the SpyderExpress calibration software displays. The puck has a suction cup for attaching to the surface of your monitor; you should occasionally tap it to maintain the suction.
After you click the Next button, just sit back and let the calibration run.
Once installed with the puck in place, the calibration software measures the output from the display, and sets it accordingly.
The calibration process adjusts your monitor to settings that the tool determines are accurate. This basic tool doesn’t allow any manual tweaks, so you’ll need to choose a more expensive model if you want to be more involved.
In my experience, the photographs I’m editing these days look correct, now that I've done a proper monitor calibration. Having a correctly calibrated monitor helped me discover that Photoshop’s Camera Raw application often blows out the highlights of my photographs by setting the brightness too high. Now I can see how garish the changes are, and dial them back accordingly.
The bottom line: If you’re interested in photography or video, calibrate your display. Even if all you do is the basic Windows calibration, it’s still better than simply staring at weird-looking images and wondering what’s wrong.
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