Adobe Photoshop CS5 for Photographers - Martin Evening [274]
If you don't have a display calibration device you can always build a profile for your display using a visual calibration method. You could, for example, use the Display Calibration Assistant that comes with the Mac OS X system. However, the problem with relying on visual calibration is that because our eyes are so good at adapting to light, our eyes are poor instruments to use when calibrating a device like a computer display. In Chapter 2 I mentioned some of the equipment and software options that you can buy these days and showed a quick run-through of how to calibrate a computer display with a calibration device. I would strongly urge you to purchase a proper measuring instrument and use this to calibrate the display on a regular basis. A hardware calibration device combined with a dedicated software utility is the only way that you can guarantee getting good color from your system, as this will enable you to precisely calibrate your display and build an accurate display profile. At the time of writing, I have found four basic display profiling packages, which include a colorimeter and basic software program, all for under $300. Highly recommended is the basICColor Display and Squid combination. Then there is the X-Rite Eye-One Display 2 that comes with Eye-One Match 2 software, the Monaco Optix XR system and lastly the ColorVision Monitor Spyder and Spyder2 Pro Studio. Of these I would probably recommend the X-Rite Eye-One Display 2, since I am very familiar with the (more expensive) Eye-One spectrophotometer system, which I use to calibrate and profile the display in my office (Figure 12.8). It is also an emissive spectrophotometer so I can use it to build custom printer profiles as well. The other units I have listed here are all colorimeters so these can only be used for building monitor profiles, but they are usually regarded as being equally as good as the more expensive spectrophotometers for this type of task.
Figure 12.8 Good color management is very much dependent on having your display calibrated and profiled. This should ideally be done using a hardware calibration device such as the X-Rite Eye-One system.
Calibration and profiling
Profile measuring devices can be attached to the display by hanging the device over the edge of an LCD display using a counter weight that gently rests the calibrator against the surface of the screen. Whatever you do, don't use a calibrating device with suckers on an LCD as this can easily damage the delicate surface.
LCD hardware calibration
Some high-end LCD displays are also beginning to feature hardware-level calibration such as Eizo Coloredge and Mitsubishi Spectraview.
The software packages used will vary in appearance but they essentially all do the same thing. Before you build a profile there are several option settings you have to decide upon. First there is the gamma space which I recommend should be 2.2 (even if it says somewhere that Macintosh users should use 1.8), although for LCD screens you should probably use the ‘native gamma’. The white point should be set to 6500 K, or with LCD displays you can use the native white point. If given the option, save a small profile size for CRT profiles and a large profile size for LCD profiles. The first stage is to calibrate the display to optimize the contrast and brightness: 120–140 candelas m2 is ideal for a desktop LCD display and 100–110 CD m2 is the ideal luminance for laptops. Once this has been done you will want to lock down the hardware controls so they cannot be accidentally adjusted. This should be done before performing the calibration in which a series of colors are sent to the display and the measurements used to adjust the video card settings, which will fine-tune the display to achieve optimum neutralization.
The second part