UPDIG Photographers Guidelines | version 4.0
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Monitor Calibration
Computer monitors must be calibrated and profiled before they can be part of a professional workflow. Accurate monitor calibration and creation of a display profile require a hardware device, such as the X-Rite EyeOne Display 2 or Color Vision Spyder 3 Elite. Another useful tool is a Profile Verification Kit (such as this one by Pixl Ltd). This is a digital file with an accompanying proof or print. After profiling your monitor, you view a comparison between the digital file, displayed in Photoshop (or other professional imaging software), and the proof print, as viewed under 5000K/D50 lighting, to indicate whether your monitor profile is accurate. If your work requires inkjet prints for display, you may do better to evaluate the images under 6500K/D65 lighting — and in some cases a dual-color viewing booth could be a useful investment.

working environment
No matter how good your monitor or how well you have it calibrated and profiled, you must ensure your work environment features subdued, neutral lighting that does not vary. Your computer desktop should be set to a neutral gray, and you should avoid having areas of bright color within your field of vision, or reflected in the monitor. This includes brightly colored clothing or brightly colored blinds, as any color reflected on the screen will likely influence your perception of the color displayed. If blocking off all windows in your editing room is not feasible or desirable, you can still achieve some measure of accuracy by creating a "daytime" profile and a "nighttime" profile, switching between the two.

display types
The two most common types of display technology in use today are LCD and CRT. LCD (liquid crystal display) monitors are rapidly replacing CRT (cathode ray tube) displays. Production of professional-grade CRTs, such as the Sony Artisan, has ceased. LCD displays with LED backlighting show a very wide gamut that closely matches the Adobe RGB color space.

Calibrate CRT monitors before profiling, since they have hardware controls for their RGB amplifiers, as well as controls for black level and luminance. First, use the hardware device and software to adjust the RGB guns to the desired white point (often called color temperature, although this is a slightly different concept) and black point (if available on your display system). Next, profile the calibrated CRT. Color-savvy programs, such as Photoshop, then use the profile to display accurate color.

LCD displays often only have brightness controls, although some also have contrast settings, too. Some LCDs also have color temperature controls, but these actually only adjust the CLUT (color look up table. If the adjustment differs substantially from the native color temperature, this can cause reduced color gamut and banding. For that reason, when profiling an LCD, it is best to adjust only the brightness control and any contrast control, then let the profiling device set the desired white point through the display profile.

direct digital communication (ddc)
DDC allows adjustment of the display's brightness, contrast, white point and gamma through the profiling device and software. This will save time and improve precision when calibrating and profiling monitors. When shopping for a new monitor, its best to choose a DDC-compliant display if possible.

monaco optix guide
Regardless of whether you use their product, Monaco has an excellent PDF manual that explains in detail how to calibrate and profile both CRT and LCD monitors.

white point and gamma
The purpose of monitor calibration and profiling is to create a situation where the image on your monitor closely matches the image as it will appear on a print, a proof, a press sheet — or, if your work is destined for the web, as viewed on the average un-calibrated PC or Mac monitor. Desired white points range from 5000K (yellow-red) to 6500K (bluer). The gamma correction may vary from 1.0 to 3.0, or be based on L* gamma. The monitor's luminance may vary from 80 cd/mē to 140 cd/mē. Adjust these settings based on viewing conditions. If comparing the monitor with proofs in a viewing booth, adjust to the best match. The correct luminance also depends on ambient light conditions. High-end color work should take place in ambient light controlled for color temperature, flare and luminance. For work in bright office or studio environments, you might need a luminance of more than 140 cd/m2 to see shadow detail on your monitor.

There is no single standard for white point, gamma and luminance, because there is no standard for what you are trying to match. If you are working in pre-press, you will want to match press proofs and press sheets. For this, you may find a white point of 5000K or 5500K will give you the best match of monitor to proof or press sheet viewed under a 5000K light. The appropriate luminance may be around 100cd/m2. If you are preparing files for ink-jet or Lightjet printing, you may find that a white point of 6000K or 6500K will give you the closest match, although you should always view the prints under the color temperature of the lighting where they'll be displayed. Once again, monitor luminance should match the appearance of the display prints in the viewing condition. Prepare image files for the web on a monitor calibrated and profiled to the sRGB standard gamma of 2.2 and white point of 6500K. This will be a compromise between the uncalibrated Mac gamma standard of 1.8 and the uncalibrated PC standard of 2.4. It is also a reasonable compromise between a prepress monitor calibrated to 5000K and an uncalibrated PC monitor, which may be in the 7300K-9300K range. Modern LCD monitors usually have a native white point around 6500K.

native white point
Some argue for creating monitor profiles using native color temperature and native gamma, and let your eyes adjust to the difference between the monitor and the print or proof. Doing so will ensure you get the widest dynamic range the monitor can produce. It will also minimize artifacts, banding and posterization, which become more noticeable as you force a monitor (especially a standard, 8-bit monitor) farther from its native white point and gamma. If you do choose a custom white point and gamma, it is a good idea to evaluate the resulting profile with a utility such as Dry Creek Photo's Black Point Check and Grayscale Test. That stated, if your goal is matching your monitor to your prints, or more critically, a printer's proofs, choosing native white point is not the best practice. Minor banding is much less of an issue than failure to match print output.

more about gamma
There are more choices for gamma than 1.8 and 2.2. Some calibration software allows you to choose a custom gamma. Other software allows you to edit the gamma curve, and one product, Integrated Color's ColorEyes Display, has "L* gamma," which creates separate tonal curves for the shadow areas, midtones and highlights. It reportedly provides smoother transitions, and therefore more accurate color reproduction. If you are working in Adobe Photoshop, monitor gamma will not affect the appearance of image files, since Photoshop automatically corrects the gamma of the image as it is displayed on the monitor. Choosing a gamma has more to do with allowing your monitor to operate in its particular sweet spot, and avoiding loss of gamut, banding or posterization that may appear if you force it to run too far from its native gamma.

monitors of the future
The current TFT-LCD technology uses a white fluorescent backlight. NEC has produced a new type of LCD that uses red, green and blue LEDs (light emitting diodes) that combine to produce a white backlight. The advantages are a wider color gamut, greater dynamic range, and the ability to adjust the white point without compressing the color gamut. The NEC MultiSync LCD2180WG-LED was the first commercially available monitor of this kind. Although still very expensive as desktop displays, LED display technology has even emerged in some of the new Apple laptops.
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