Have you noticed that your printed photos sometimes don't match the image you see on your computer screen? There can be plenty of reasons why, but most are due to one or more incorrect areas of your Color Management workflow. Often, these issues might turn out to be a lack of proper monitor calibration, including Whitepoint, Gamma and/or an incorrect setting of the Colorspace the files are view and corrected within. Here are some quick tips to check on your settings.
Whitepoint is actually the color balance of the monitor screen measured in degrees Kelvin, (see Tim's article about Color Temperature for more information) and can vary widely from device to device. The most reliable calibration will be achieved by using a plug-in device that measures the output of your computer screen. The probe is packaged with software that will take you through a step by step procedure to accurately set your monitor to the correct gamma and whitepoint. The software will also create a monitor profile that will minimize variations in visual output for your specific monitor. These products are available in a variety of styles, features and price ranges. If you plan to do any color correction to your digital files , it is an essential tool to have. Because electronic devices can gradually change with useage, you will need to verify and recalibrate your monitor every few weeks or months, depending on amount of use.
Gamma refers to a specific value of brightness and contrast. One of the key differences between MAC's and PC's is the Default Gamma used on each platform. MAC's generally use a gamma setting of 1.8, and PC's use a setting of 2.2. Since we use the sRGB color space on our Noritsu Pro 32 Digital imaging equipment the 2.2 setting should be used since it is the default gamma defined within the sRGB Colorspace. In addition, most monitors are capable of accurately representing colors only in sRGB. You will want to make sure that the default working color space in Photoshop or raw file processor is also set to sRGB.
Photographers that end up publishing their images for advertising or magazines will probably want to stay in the Adobe 1998 RGB colorspace since this works better when CMYK conversion is required for offset printing. Unfortunately, to accurately view and correct digital images in this space you will need to upgrade your monitor to a device that is capable of displaying the extended dynamic color range. We use Adobe 1998 when capturing images with our Powerphase FX scanning back and when printing on our Epson 9900 printer to make Studio Giclee’s. Although files shot in Adobe 1998 can be converted to sRGB, this will simply add time to file preparation with no direct quality benefit when printing to photo output devices like our Noritsu Pro 32 Digital equipment. Mismatches of these two color spaces can produce unintended results, so be sure to submit files in the appropriate color space for the desired output type. When setting the defaults, use “Perceptual” as the rendering intent.
Finally, make sure that your monitor is located in a stable viewing environment where the ambient lighting will always be about the same. CRT displays generally offer better color accuracy than LCD flat panels, but are becoming very difficult to obtain. Avoid laptop displays for critical color correction since they often tend to be “cold” and contrasty and usually don't provide a satisfactory means of color and/or density calibration. This leads to files that are corrected improperly and can print excessively warm and flat.
For information on monitor calibration, see our article in the Preview Gallery Support Section.