lcd touch screen calibration free sample

Your new computer is ready and just waiting for that nudge of the mouse. Wait! Wasn"t there something else? Monitor color calibration is one of the basic steps most of us forget or ignore.

Pixel perfect monitor calibration is a cardinal rule for photographers and graphic artists. If you are either of those, you know all about monitor calibration. Others should read on.

A good monitor is expensive. But its impact will be lost if you don"t take the pain to carefully (and intermittently) calibrate your monitor. The colors on the screen may not be the exact match of what they actually are.

Graphics professionals will pick up serious color accuracy test tools for the job, like the Datacolor Spyder5Elite S5EL100 Monitor Calibration System. Some of you will go with the default monitor calibration software built into the OS. But we can also take some online help from these simple monitor calibration websites that have existed for a long time.

Conveniently, Windows comes with its down display calibration tool. Previously part of the Control Panel, Microsoft moved it to its own standalone app in Windows 11.

To open the Display Color Calibration tool, press Windows + S or open the Start menu, search for "calibrate display color," then open the matching result, and follow the on-screen instructions.

To manually open the ClearType Text Tuner, press Windows + S, search for "adjust ClearType text," then follow the on-screen instructions. On each of five screens, you"ll select the text samples that look best to you.

Photo Friday is a photography site. Think of the challenges involved in adjusting the brightness and contrast of a shot, and you get the reason you should calibrate your monitor. So, head to the link for their monitor calibration tool beneath the homepage, or hit the link above.

The site offers this simple one-page monitor calibration tool to adjust the brightness and contrast of your screen thanks to the gray scale tones. The idea is to tweak the monitor settings (or buttons) so that you can clearly distinguish the transition of tones from true black to true white. After calibration, the blacks should look black and without any hint of gray.

The instructions start off by telling you to dim the lights and hit F11 for viewing the gray scale chart in full-screen mode. Observe your monitor from your normal viewing distance.

The Lagom LCD Monitor Test Pages are a far more comprehensive set of tools than Photo Friday. The site includes a series of test patterns that start from checking contrast to checking for response times of your monitor. It is recommended to go through the tests in the order they are placed.

For a beginner, it might seem overwhelming. But, the test patterns come with helpful explanations. The developer also states that you can put the images on a USB drive and try them in the computer store when shopping for an LCD monitor. A 120 KB ZIP file download is included.

The Online Monitor Test website has a range of interactive tests to fix your screen colors. The menu appears when you move your mouse to the top. It starts off with a test that checks the brightness and contrast across the B/W tonal spectrum. It is similar to the test we covered on the Photo Friday website.

Next, the Color Range test checks if your monitor can smoothly produce color gradients. From the menu, you can pick different color charts. Look for “ghost images” or image trails in the Trailing test. Move the box across the screen and check if any trails are produced. The controls and options to change the color and shape of the box are placed at the bottom.

The Homogeneity test helps to pinpoint damaged pixels and faulty monitors with backlight bleeding. 1:1 Pixel mapping and testing for a blurring of Text are the last two tests on the lineup. While the former is not so much an issue with LCD computer monitors, the latter is worth a tryout if you feel that screen text is not crisp enough.

This single page screen calibration chart has few of the test images we have already covered in the earlier tools. Go through the color, gray scale, and gamma adjustments.

If the resolution setting does not match the screen, the touch position will also be affected. For example, when you touch certain positions on the screen, it responds on correct points, but clicks on other positions may activate other areas next to them instead.

When the cursor is on the desktop, right click for the setting menu → click [Display settings ] → choose the touch screen (number 2 screen) and select the corresponding resolution(for example, On-Lap M505T resolution is 1920x1080), and then click "Apply".

You can do verification measurements to assess the display chain"s (display profile - video card and the calibration curves in its gamma table - monitor) fit to the measured data, or to find out about the soft proofing capabilities of the display chain. You can also do a profile or device link (3D LUT) self check without having to take any further measurements by holding the “alt” key on your keyboard.

To check the fit to the measurement data, you have to select a CGATS testchart file containing device values (RGB). The measured values are then compared to the values obtained by feeding the device RGB numbers through the display profile (measured vs expected values). The default verification chart contains 26 patches and can be used, for example, to check if a display needs to be re-profiled. If a RGB testchart with gray patches (R=G=B) is measured, like the default and extended verification charts, you also have the option to evaluate the graybalance through the calibration only, by placing a check in the corresponding box on the report.

Note that both tests are “closed-loop” and will not tell you an “absolute” truth in terms of “color quality” or “color accuracy” as they may not show if your instrument is faulty/measures wrong (a profile created from repeatable wrong measurements will usually still verify well against other wrong measurements from the same instrument if they don"t fluctuate too much) or does not cope with your display well (which is especially true for colorimeters and wide-gamut screens, as such combinations need a correction in hardware or software to obtain accurate results), or if colors on your screen match an actual colored object next to it (like a print). It is perfectly possible to obtain good verification results but the actual visual performance being sub-par. It is always wise to combine such measurements with a test of the actual visual appearance via a “known good” reference, like a print or proof (although it should not be forgotten that those also have tolerances, and illumination also plays a big role when assessing visual results). Keep all that in mind when admiring (or pulling your hair out over) verification results :)

There are currently two slightly different paths depending if a testchart or reference file is used for the verification measurements, as outlined above. In both cases, Argyll"s xicclu utility is run behind the scenes and the values of the testchart or reference file are fed relative colorimetrically (if no whitepoint simualtion is used) or absolute colorimetrically (if whitepoint simulation is used) through the profile that is tested to obtain corresponding L*a*b* (in the case of RGB testcharts) or device RGB numbers (in the case of XYZ or L*a*b* reference files or a combination of simulation profile and testchart). If a combination of simulation profile and testchart is used as reference, the reference L*a*b* values are calculated by feeding the device numbers from the testchart through the simulation profile absolute colorimetrically if whitepoint simulation is enabled (which will be the default if the simulation profile is a printer profile) and relative colorimetrically if whitepoint simulation is disabled (which will be the default if the simulation profile is a display profile, like most RGB working spaces). Then, the original RGB values from the testchart, or the looked up RGB values for a reference are sent to the display through the calibration curves of the profile that is going to be evaluated. A reference white of D50 (ICC default) and complete chromatic adaption of the viewer to the display"s whitepoint is assumed if “simulate whitepoint relative to display profile whitepoint” is used, so the measured XYZ values are adapted to D50 (with the measured whitepoint as source reference white) using the Bradford transform (see Chromatic Adaption on Bruce Lindbloom"s website for the formula and matrix that is used by DisplayCAL) or with the adaption matrix from the profile in the case of profiles with "chad" chromatic adaption tag, and converted to L*a*b*. The L*a*b* values are then compared by the generated dynamic report, with user-selectable critera and ΔE (delta E) formula.

It sets the nominal (target) L* value to the measured L* value and a*=b*=0, so the profile is effectively ignored and only the calibration (if any) will influence the results of the gray balance checks. Note that this option will not make a difference for a “Single curve + matrix” profile, as the single curve effectively already achieves a similar thing (the L* values can be different, but they are ignored for the gray balance checks and only influence the overall result).

If you enable “Use absolute values” on a report, the chromatic adaptation to D50 is undone (but the refrence white for the XYZ to L*a*b* conversion stays D50). This mode is useful when checking softproofing results using a CMYK simulation profile, and will be automatically enabled if you used whitepoint simulation during verification setup without enabling whitepoint simulation relative to the profile whitepoint (true absolute colorimetric mode). If you enable “Use display profile whitepoint as reference white”, then the reference white used for the XYZ to L*a*b* conversion will be that of the display profile, which is useful when verifying video calibrations where the target is usually some standard color space like Rec. 709 with a D65 equivalent whitepoint.

In the previous article, I described the steps needed to install an LCD touchscreen on the Raspberry Pi. In this article, I will show you how to adjust the screen rotation of the LCD to landscape mode, and will show you how to calibrate the touchscreen pointer for optimal accuracy. Just follow the steps below to compete the process of setting up your Raspberry Pi LCD touchscreen:

1. First we need to change the setting for screen rotation in the /boot/cmdline.txt file. This setting is called fbtft_device.rotate=X. By default, this is set to X=0, which results in a portrait mode screen orientation. In order to switch the orientation to landscape mode, change fbtft_device.rotate=0 to fbtft_device.rotate=90. Enter sudo nano /boot/cmdline.txt at the command prompt. There should only be one line in this file. Go to the end of it and you will find the fbtft_device.rotate=X setting. Change the value from 0 to 90:

However, if you try to touch the screen now, you will find that the pointer movement does not correspond to your finger movement. This is because the LCD screen driver and the touchscreen controller driver have separate settings for screen rotation. We need to change the rotation of the touchscreen controller driver to match the rotation of the LCD screen driver.

2. You probably noticed that dragging your finger to the right moves the pointer up, not to the right. This indicates that the x and y axes of the touchscreen are swapped. To correct this, we need to swap the x axis for the y axis. This can be done by changing the swap_xy=X parameter in /etc/modules.

Now if you drag your finger around the screen, you will notice that the y axis (up and down) is correctly aligned with the motion of your finger. However, the x axis (left and right) is still inverted. To fix this, we need to install two more kernel modules, xinput and evtest. xinput is a Linux utility that will allow us to configure input device settings for the touchscreen controller, and evtest is an input device event monitor and query tool.

After the Pi finishes rebooting, you should notice that when you move your finger across the touch screen, the pointer should follow correctly in both axes. If you are using the Raspberry Pi 2 Model B, you will need to complete the calibration steps below before the pointer follows your finger correctly (and make sure that you have enabled startx to load automatically – see step 6 in this article).

You can rotate the screen 90 degrees (as we did in this tutorial) and the power connector will be at the bottom of the screen, but you can also rotate it 270 degrees so that the power connector is at the top of the screen. To do this, simply enter fbtft_device.rotate=270 in the /boot/cmdline.txt file. Then change the DISPLAY=:0 xinput --set-prop "ADS7846 Touchscreen" "Evdev Axis Inversion" 0 1 line in the /etc/X11/xinit/xinitrc file to DISPLAY=:0 xinput --set-prop "ADS7846 Touchscreen" "Evdev Axis Inversion" 1 0. All you need to do is switch the values of the 0 and 1 at the end of this line.

Now that we have our LCD touchscreen up and running, the final step in the installation is the calibration of touch control. This will make the pointer much more accurate and easier to use.

2. Now we need to install the calibration tool we will be using, xinput_calibrator; and other filters for controlling the touchscreen response. Install the tslib library by entering aptitude install libts-bin:

3. The calibration tool we will use is called ts_calibrate. We will also be using a program to check the results of the calibration called ts_test. In order to use ts_calibrate and ts_test, we must first set proper environmental variables. Enter export TSLIB_TSDEVICE=/dev/input/event0 into the command prompt, then enter export TSLIB_FBDEVICE=/dev/fb1:

4. Now we can use ts_calibrate. Enter ts_calibrate at the command prompt (make sure you are still in root mode) to run the ts_calibrate program. The program will consecutively display five crosses on different parts of the screen, which you need to touch with as much precision as possible:

This calibration data will be written to a calibration file called /etc/pointercal. To view the contents of this file, enter cat /etc/pointercal at the root command prompt.

Drag the cross around the screen and observe how closely it follows your finger or stylus to test the accuracy of the calibration. Now press the “Draw” button to enter the drawing mode:

This is kind of a long process, but it is well worth it if you want to get the LCD touchscreen set up properly. So if you have any trouble setting this up or have anything to say, please leave a comment below. Also, if you found this article useful, please share it with your friends!

Both MacOS and Windows have built-in calibration tools to help guide you step-by-step through the process, which is particularly helpful if you are new to monitor calibration. These free tools should be the first stop if you’re merely a casual image junkie or working on a tight budget. Keep in mind that the adjustments will be limited by the display type and model, though.

In older versions of Windows, you can find the Color Calibration utility in the Display section of the Control Panel, which is listed under Appearance and Personalization.

Step 2: Now that you are in the calibration tool, follow the on-screen instructions to choose your display’s gamma, brightness, contrast, and color balance settings.

Step 3: Once the calibration wizard is complete, make sure to choose the Current calibration, or return to the previous calibration if you are unsatisfied with the results. The new calibration will be stored as an .ics file, or color calibration file, and will show up as a new International Color Consortium (ICC) Profile in the Color Management settings app.

Step 2: Your Mac’s step-by-step instructions will walk you through the calibration process once you have found and opened the software utility. Just follow the on-screen instructions to choose:

Color adjustments: White point is a given, but Apple will try to detect your display and offer a number of other color calibrations at this point … or it may skip the rest of the adjustment options entirely. Native Apple displays may be more likely to have fewer color calibrations at this point (because Apple already calibrated them).

There are a handful of web-based calibration tools that help you manually adjust your monitor settings. They can provide more precise, or more customized, calibration than the built-in utilities.

W4zt Screen Color Test: This simple webpage provides you with several color gradients and grayscale color boxes you can use for quick comparisons, along with an easy gamma test you can run. It’s nice to have so many tests on one page, making this solution great for fast and dirty calibration so you can move on.

The Lagom LCD Monitor Test Pages: Handy for both online and offline use, the Lagom LCD Monitor Test Pages not only allow you to adjust various things such as contrast and response time, but also allow you to download the images as a 120KB zip file, so you can check any monitor in-store that you are thinking about purchasing.

Calibrize 2.0: If you want a great tool that goes a little more in-depth than native calibration options, we suggest downloading Calibrize 2.0. It’s an excellent free wizard that carefully walks you through well-explained steps to help you calibrate color, grayscale, gamma, and similar settings on your computer.

While they’re better than a more temporary solution, built-in calibration utilities still have one major flaw: You. Since they rely on your specific color perception, what looks great to you might look thoroughly off to a friend.

If you’re looking for a calibration tool, we recommend either the X-Rite ColorMunki Smile ($99) or the Spyder5Elite ($200). Both devices boast a full-spectrum, seven-color sensor that can accurately display a range of standard and wide-gamut displays. If you have a bigger budget, you can look for upscale calibrators that have even more advanced options.

These devices are user-friendly, involving a simple three-step process of fastening the device to your screen, plugging it into a USB port, and opening the calibration software. When the software starts running, you just have to follow the setup procedure. It’s fairly intuitive, but if you have trouble, you can find tutorials online that will walk you through it.

Starting at $180, X-Rite’s i1Display is another solid device. Just like the Spyder series, each of these three options is configured with automated calibration software. The more money you spend, the more additional features and other benefits you’ll get from the device.

Calibrating your touch screen is a cinch, but the method will vary depending on which operating system you are running. These instructions will work with any model of Toughbook that comes with a touch screen. In fact, these instructions should work with any touch screen laptop.

If you’re running Windows 7, Windows 8 or Windows 10, you should already have a touch screen calibration tool. To find it, open up the start menu and begin typing “calibrate.” An item should appear labeled

Calibrate…. If you have a dual touch screen, you’ll get a message asking if you’d like to calibrate the pen input or touch input. Select whichever one you want to calibrate.

A white screen will appear with thin lines around the perimeter, about a half inch in from the edge of the screen. Somewhere along these lines will be a darker black crosshair. Touch the center of the crosshair, either with your pen or your finger, depending on which input you are calibrating (if you have a resistive touch screen like the one on a Toughbook CF-31 or some CF-19 models, it’s a good idea to use a stylus, but you can use a finger if you want).

After you tap the crosshair, another will show up somewhere else along the edges of your screen. Tap that one as well and repeat the process until it asks you if you want to save the calibration data. If you’re happy with your tapping accuracy, click OK. Otherwise, click cancel and start the process over. If your touch screen has more than one type of input (as with a dual touch model), you can calibrate it using the same method.

The previous instructions assume your touch screen mode is set to Auto, and, unless you’ve gone into your laptop’s Basic Input/Output System (BIOS) and deliberately changed something, it probably is. If, however, you still can’t get your touch screen calibrated, your touch screen mode may be set to “Touchscreen Mode.”

If you are not sure and you want to check, you can get to the BIOS by pressing F2 as soon as the Panasonic logo appears when booting up your laptop. Once in the BIOS, look for a setting called Touchscreen Mode. It should be set to either[Touchscreen Mode]or [Auto]. If it"s set to Auto, you can either try the above instructions again or leave a comment below and we’ll do our best to help. If it"s set to Touchscreen Mode, you can either change it to Auto or leave it as Touchscreen Mode and use the following method.

To calibrate in this mode, you’ll be using the Fujitsu calibration utility, which comes with the Panasonic touch screen driver. If your touch screen is working at all, you should already have the Fujitsu calibration utility. Open the Start menu and start typing “calibration” in the search box. Under Programs, you should see an item called Touch Screen Calibration Utility. Click it to open the Fujitsu calibration utility.

Similarly to the Windows touch screen calibration tool, crosshairs will appear around the edges of the screen. The biggest difference here is that the crosshairs are red instead of black. Touch each one, working your way around the screen until the crosshair reaches its starting point. After you’re done, hit the enter key and begin dragging your stylus or finger around the screen to test the calibration. Once you’ve tested your calibration, press the enter key again to save the changes and exit.

Calibrating your touch screen on Linux may be a bit more complicated than it is on Windows, as every flavor of Linux is a little different. Some Linux distros already come with a touch screen calibration utility, but for our purposes we’ll assume that we need to install one. These instructions will also assume you are using Apt as your package manager (the default in many distros, including Debian, Ubuntu, and all their variants and derivatives). If you are using

Tap each crosshair that appears on the screen. Once you’re done, the terminal will spit out some more text. Select and copy the portion that starts with

To make the calibration permanent (i.e. it won’t reset itself if you restart your computer), you’ll need to paste the data you just copied into a config file. We’ll do this using a simple text editor called Nano, which runs in the terminal (Nano is pretty ubiquitous, but if you have some oddball distro that doesn’t have it, feel free to use the editor of your choice):

Paste the data into the empty text file, hit Ctrl+X to exit and Ctrl+Y to save, then hit enter. Your touch screen is now calibrated and should stay that way even if you restart your computer.

If you are having issues with your Touchscreen, this may include being unable to access items to the edge of the screen. For example, your screen may require re-calibration.

NOTE: If Tablet PC Settings is not seen, then make sure that your touchscreen USB cable is attached if using external display. Also check that any touchscreen drivers are installed, you can download these from the Dell Support site.

The touch screen may start to lose its sensitivity due to foreign particles (such as sticky notes) that are blocking the touch sensors. To remove these particles:

Use a clean, lint-free cloth to wipe the surface and sides of the touch screen to remove any dirt or fingerprints. You may spray mild, non-abrasive cleaner or water on the cloth if needed, but not on the screen.

If you do not have Cortana enabled, Then either click the Start button on screen or use Windows key on keyboard. Then click Settings icon (cog). Then type Tablet Mode in the settings search box and select Tablet Mode Settings.

The RPi LCD can be driven in two ways: Method 1. install driver to your Raspbian OS. Method 2. use the Ready-to-use image file of which LCD driver was pre-installed.

3) Connect the TF card to the Raspberry Pi, start the Raspberry Pi. The LCD will display after booting up, and then log in to the Raspberry Pi terminal,(You may need to connect a keyboard and HDMI LCD to Pi for driver installing, or log in remotely with SSH)

1. Executing apt-get upgrade will cause the LCD to fail to work properly. In this case, you need to edit the config.txt file in the SD card and delete this sentence: dtoverlay=ads7846.

This LCD can be calibrated through the xinput-calibrator program. Note: The Raspberry Pi must be connected to the network, or else the program won"t be successfully installed.

Disappointed by your monitor’s image quality? You might be able to improve it through monitor calibration. Learning to calibrate your monitor will make the most of its potential, and while you can purchase expensive tools for this task, you can often achieve a noticeable improvement without them.

Windows and MacOS have very basic built-in calibration utilities. They’re limited and won’t help you understand how your monitor works, but they’re a good place to start.

The calibration utilities in Windows 10 and MacOS are only a start. They will help you work out serious problems with your calibration, like an incorrect contrast setting or wildly terrible display gamma value. They’re more focused on providing a usable image than an enjoyable one, however. You can do more.

Before we get started, let’s bust a popular myth about calibration: there is no such thing as a perfect monitor or a perfect calibration. Image quality is subjective and, for most people, the goal of calibration should be improving perceived quality on the monitor you own.

You don’t need to target these standards. In fact, precisely targeting a standard is impossible without a calibration tool. Still, you’ll want to be aware of these standards as you calibrate your monitor because they’ll impact how certain monitor settings work. Also, many monitors have settings meant to target them.

Nearly all monitors sold in the last decade have a backlit LCD display. This means they have a LCD panel with a light behind it. The light shines through the LCD to produce an image (otherwise, it’d look like the Gameboy Color).

To calibrate contrast, visit the Lagom LCD contrast test image. An ideal contrast setting will let you see all color bars from 1 to 32. This can be a real challenge for an LCD monitor, especially on the dark end of the image, so you may have to settle for a lack of visible difference in that area.

On the other hand, setting the contrast too high will cause colors at the high end of the spectrum to bleed into one. This problem is avoidable on a modern LCD monitor by turning down the contrast which, in most cases, is set to a high level by default.

You need a calibration tool to precisely adjust gamma, but you can make improvements using the Lagom LCD gamma test image. As its instructions say, you’ll want to sit back from your monitor (about five or six feet away) and look at the color bars, each of which is made up of several bands. You’ll see a point on each bar where the bands start to blend together. The gamma value indicated where this occurs is your monitor’s approximate gamma value.

Your monitor may include gamma settings in its on-screen control menu. Less expensive monitors will have a selection of vaguely labeled viewing modes, like “office” or “gaming,” with their own prebaked settings. You can flip through these while viewing the Lagom LCD gamma test image to see if they improve the gamma.

No test image can help you target a specific white point. You need a calibration tool for that. However, most monitors will have several color temperature settings that you can flip through in the monitor’s on-screen menu.

Less expensive monitors will use vague values, such as “warm” and “cool,” while more expensive monitors will provide precise color temperature adjustments, such as “5500K” or “6500K.” MacOS includes color temperature adjustment as part of its default display calibration.

So, how do you dial in color temperature without a calibration tool? I find it’s best to view a blank white screen, such as a new image or document, and then flip through the available color temperature settings. This will help you settle on a setting that fits your preferences.

In the end, color gamut isn’t a very useful part of monitor calibration for most people. Try the sRGB or DCI-P3 modes, if available, but be prepared for disappointment if those modes lock your monitor’s brightness and gamma.

If you want to take calibration to the next level, however, you need a calibration tool. A calibration tool has a sensor that can judge whether your monitor’s image conforms to accepted standards like sRGB and DCI-P3. This is especially important for color accuracy. There’s no way to gauge color accuracy with the naked eye.

Datacolor’s SpyderX Pro is my preferred calibration tool. The SpyderX is extremely fast and simple to use, which is important, as calibration can become confusing and time consuming. The SpyderX Pro is great for most people and priced at a relatively affordable $170. X-Rite’s i1Display Studio is another good option, though I haven’t used the latest model. It’s also priced at $170Remove non-product link.

If you do buy a tool, you can throw most of the advice in this guide out the window. Calibration tools come with software you’ll use with the tool and, after calibration, will load a custom display profile.

A monitor calibration tool has become less important as monitor quality has improved. I’ve reviewed monitors for over a decade, so I’ve witnessed this progress first hand. Today’s monitors are more likely than ever to have acceptable contrast, gamma, and color out of the box. Most ship at a default brightness that’s too high, but that’s an easy fix.

Even content creators may not need a calibration tool. Calibration is often considered a must for professionals, but the definition of professional is not what it used to be. Tens of thousands of self-employed creators make excellent content without ever touching a calibration tool. These creators don’t have to conform to any standard aside from what they think looks great. It’s true some creators have a reputation for remarkable image quality and slick editing, but most just use whatever they have at hand.

You have to just add number by touching on screen, maximum digits per number allowable is 4 and then select operator and add again second number, press on equal. Finally, you got the result on screen, Congratulation you have made your own Arduino Calculator with TFT Display.

It is very important part of the project, you have to calibrate. if you don’t calibrate touch screen, This project may not work or you will get wrong output when you are pressing touch screen.

After pressing all the mark, you will get the result on screen as well as on serial monitor and I suggest you to open serial monitor, before starting calibration.

Download the Adafruit_ILI9341esp zip (color screen) and XPT2046 zip (touch sensor) files.  Install these by running the Arduino program and going to the Sketch –> Include Library –> Add .ZIP Library… menu.  Add each ZIP file individually.

Calibration is the process of setting the monitor to the desired neutral output. It includes settings for luminance, white point and gamma. Once it"s been neutralized as well as the monitor"s controls allow, it"s time to measure the color and help to perfect it with software.

Profiling is the process of measuring the imperfections in the monitor, and creating a "filter" that compensates for those imperfections. Using the parameters set in the calibration step, profiling requires using a hardware device, often referred to as a "puck" (a Colorimeter or Spectrophotometer), that hangs over the monitor screen and reads several sets of red, green, blue and grey patches generated by the profiling software. The color patches are measured by the puck as they are displayed. The differences between the colors the monitor displays in its native state and the true colors of the patches are used to create a monitor profile which will cause the monitor to display the true colors more closely than it did in its native state.

Like high-end stereo speakers, the monitor is a place where you really do get what you pay for. The best systems are precision engineered for added fidelity and evenness across the screen.

The old-school CRT monitors are pretty much out of service. They have been replaced by LCD flat panel monitors. The newest technology is a new form of flat panel that uses LED light behind the screen.

In the 1990s, high-end CRT (cathode ray tube) monitors were considered to be state of the art. That technology has gradually given way to LCD panels. Up until now, these panels have used CCFL (cold cathode fluorescent lamp) back lights. CCFL technology is in the process of being replaced by LED (light emitting diode) backlights. LED backlights have many advantages over CCFL including requiring half the power consumption and, more importantly, they are free of mercury, a toxic material that is emitted by electronic equipment. LED backlights have another advantage: the white light they create is derived from pure red, blue and green LEDs, so the light is purer, brighter and can offer a wider color gamut than CCFL. Some LED panels that are currently available have up to 120% of the Adobe RGB (1998) color gamut, which is 25% more than the very best CCFL panels. Most likely your next LCD will be an LED backlit display.

We can say unequivocally that this is an essential feature for a monitor to have. When you buy a new widescreen monitor you should check it for evenness. This can be most accurately done by creating a monitor profile, and then use the "validate current profile" function of the monitor profiling software to measure the four corners and side-to-side areas. If you have a spectrophotometer handy, this can be used as well. A quick-and-dirty approach is to bring up an image in Photoshop and move it around on the screen and see if it appears to get brighter or darker as you move it around.

This refers to how quickly a pixel can change colors, measured in milliseconds (ms); the fewer the milliseconds, the faster the pixels can change, reducing the ghosting or streaking effect you might see in a moving or changing image. This feature is important for watching videos or gaming but not very important if you use your monitor for editing images in Photoshop. What is important for image editing is quick screen redraw, which is governed by the amount of RAM available on the graphics card and the image cache level settings.

The best monitors come with calibration tools as part of a package. These include calibration and profiling software, and some include the hardware device or puck. These tools include DDC communication, which allows the calibration tools to adjust the monitor hardware settings directly as opposed to just adjusting the graphics card. This preserves the monitor"s dynamic range better than adjusting only the graphics card.

LCD (liquid crystal display) monitors come in several architectures. One term you may see is TFT (thin film transistor) LCD. Thin film technology improves image quality and is used in all high quality computer monitors.

In addition to TFT, other terms you may see are TN, VA, and IPS. TN (twisted nematic) technology is the most basic LCD architecture. However, TN panels are not the best for photo editing due to a limited viewing angle (meaning that the color and contrast change fairly dramatically if your viewing angle is not dead center), and low bit depth (6-bit depth is typical).

Many professional IPS-based LCD monitors also feature high bit-depth and ultra wide color gamuts, which we define as equal to or greater than the Adobe RGB (1998) color space.

One interesting variation of IPS is the AH-IPS architecture developed by LG Display. This type of IPS panel uses the AFFS (advanced fringe field switching). This architecture gives the best performance for smaller screens with high resolution, such as those used in handheld devices like the Apple iPad.

AH-IPS has the advantage of greater light transmission, which translates into lower power consumption. So far, this technology has been limited to small screens due to higher manufacturing costs for larger screens.

While some monitors have integrated devices for calibration and profiling, you might want to invest in a stand-alone device. You can get great results with many mid-priced monitors and low-cost calibration solutions.

Best practices also recommend that you check the calibration by comparing a reference file as shown on the monitor to a reference print illuminated under a high-quality light source like a SoLux lamp.

Luminance or brightness of the monitor is the most important setting (outside of creating a good color profile) for screen-to-print matching. Monitor brightness is measured in candelas per square meter (cd/m2), also sometimes referred to as "nits". The acceptable range is 80 cd/m2 to 120 cd/m2, with 100 cd/m2 being the most commonly recommended brightness for pre-press work. The brightness of the monitor is driven to a large degree by the brightness of the working environment. The brighter the working environment, the brighter the monitor will need to be.

The white point is the calibration setting on a monitor that determines the color temperature of the brightest white. Color temperature is expressed in Kelvin, eg 6500K. A more accurate unit of measuring color temperature is the so-called standard illuminant, expressed as D50, D65, etc. For most practical purposes you can use either unit of measure with your monitor calibration software. 5000K/D50 and 5500K/D55 are commonly used in CMYK reproduction, and 6500K/D65 is commonly used for general purpose and images on the web.

The native white point is the default white point of a monitor. Most high-quality LCD monitors are very close to 6500K. Less expensive monitors and many Windows operating system monitors are quite a bit bluer, having a native white point between 7300K and 9300K.

Gamma is less important than white point and luminance for photographers because color managed image editing applications such as Photoshop automatically adjust for gamma and display all images the same, regardless of monitor gamma. The Windows operating system default is a gamma close to 2.2, while Apple operating systems have used a native gamma of 1.8 up until the Snow Leopard version of OS 10. Most monitor hardware is designed to have a native gamma of 2.2 so many Mac users calibrate and profile their systems to 2.2 gamma. A few calibration/profiling software applications use a variable gamma curve called L* gamma. It is a slightly less linear version of 2.2 gamma which can result in slightly more shadow detail.

You can run the calibration routine, but you don"t actually know that everything is set up optimally until you check it against some reference standards.

In order to check the quality of your calibration, you need to examine a print under a standardized lighting setup which we refer to as reference lighting. Reference lighting is a high quality light source that is close to the D50 standard for graphic arts. This can be a lightbooth such as those made by GTI or others, or it can be a relatively inexpensive SoLux lamp. The SoLux lamp is very color accurate, but the lightbooth will produce less glare. Some lightbooths are equipped with brightness controls and some even have USB connections to the computer to provide complete control over monitor and reference lighting equalization.

For those who really want to get things perfect, the reference setup can be used to determine which white point is most appropriate for your eye and your workspace. Profile your monitor to D65 and compare the screen to the reference print viewed under the reference lighting. If the print appears to be slightly warmer than the monitor, try D60, D55 or even D50 until you find the best match of monitor to print for your system and your working environment.

Ambient lighting, otherwise known as your working environment lighting, is a critical component of your color management setup. To a large degree it will influence your choice of monitor white point and monitor brightness, the two most important variables for monitor calibration. We recommend a reasonably dim unchanging ambient light level. Avoid working in conditions where strong sunlight streams in, as it will be too bright and will change continually throughout the day and from day to day.

A term used to describe color temperature as it relates to the luminance of the brightest white that a device can display. It also refers to the reference (or target) white of the illuminant. White point is commonly used to describe the calibration setting on a monitor that literally sets the color temperature (or illuminant) of how white is displayed. Common settings include 5000 or 6500k or the D50 or D65 references. Monitor white point settings are often determined by the viewing environment and color matching requirements of a workflow.

A display technology used in computer monitors (also called flat panels) that has largely replaced CRT devices. Typically they use a cold cathode fluorescent (CCFL) backlight to illuminate the screen, which is made up of a layer of liquid crystal, further layered with positive and negative electrodes, polarizing film, and protective glass. LCD computer monitors can range from consumer-grade displays with reduced contrast, sharpness and color gamut to high-bit, wide-gamut, TFT (thin-film transistors) active matrix displays designed for digital photography and graphics applications. LCDs are also used on the back of digital cameras to provide an image preview.

LED technology is coming into wider use in computer monitors, replacing the cold cathode fluorescent (CCFL) backlights that have until recently (2009) been standard. Providing higher brightness levels, they are also considered more environmentally friendly because they do not contain Mercury (CCFL does) along with reduced energy consumption. OLED (organic light emitting diode), is an emerging, next-generation display technology that shows great promise and could replace LCD/LED backlit computer monitors in the future.