Color Management

Step 1: Calibration & Profiling

The Problem:
Your camera, computer monitor, projector and printer each displays the same color slightly differently. For example, a person’s face (which is a particular shade of red) imaged by your camera may appear to be too yellow on the monitor, too green in the projector and too orange in the printer. Said another way, a specific face color might be represented with too little blue by the monitor, too much green by the projector, and not enough cyan by the printer. Other colors may also be misrepresented by each device.

The Solution:
Calibrate and profile your monitor, projector and printer so that each device can accurately represent a set of standard colors. This will ensure the closest correspondence of colors between the devices. You can also do this for your camera, but after getting an image, most of us want to change the colors and color balance in post processing to achieve a ‘look’, which will circumvent any color calibration of the camera. So, we usually don’t bother to calibrate and profile our cameras. In post processing, we rely entirely on the computer monitor to accurately represent color. If the monitor is not calibrated and profiled, the chances are that it is not as accurate as it can be, and the same can be said of projectors and printers.

The Process:
1. Buy an appropriate calibration device. Calibration software is included.
For Camera, monitor, printer & projector: Calbrite ColorChecker Studio or Spyder X2 Elite plus Spyder Print. For Camera, monitor & projector (ie. you don’t make prints): Calbrite Display Pro HL or Spyder X2 Elite.

2. Disable settings in the Windows or MAC OS that automatically change the monitor’s brightness or color. More details are available in the first video playlist listed in the ‘Videos’ section below.

3. Use the software & calibration device to calibrate and profile your monitor (and projector and printer, if you own them). Instructional videos are listed in the ‘Videos’ section below.

What is Calibration and Profiling?
Let’s use the computer monitor as an example. Buttons on the side, bottom or back of the monitor will switch on the on-screen display (OSD) or menu, providing access to controls for adjusting brightness, contrast, and RGB color. (Projectors usually have an OSD, too.) Calibrating the monitor means making these adjustments so that they are as close as possible to a standard. Standard test patterns are displayed on the screen while the monitor’s OSD is used to adjust brightness and contrast. Calibration software, a calibration device and the monitor’s OSD color controls are used to adjust the monitor’s R, G & B color balance as close as possible to 6500 degrees K (D65). These adjustments may not be fine enough to be perfect. Even after calibration, the monitor’s electronics usually cause imperfections in the monitor’s display of thousands of different colors. So, the additional step of profiling is necessary.

Profiling is the process of using the calibration software and the calibration device to make a lookup table (LUT) that lists corrections for the discrepancies between true standard colors and the colors that the calibrated monitor displays. These corrections are stored in a file with an .icc or .icm extension, and the file is called a monitor profile. The corrections in the .icc or .icm profile file are used by the computer’s operating system (Windows, Mac, Linux) to alter the RGB color signals sent from the graphics processor (GPU) to the monitor, so that the monitor displays standard colors accurately.

How Often Is Re-calibration & Re-profiling (R&R) Necessary?
With monitor use over time, the specs of electronic components inside the monitor change slightly, and that changes color accuracy. Therefore, it is usually recommended to R&R every 1-3 months, depending on monitor use. Some professionals R&R at the start of each project. In printers, color accuracy depends on ink cartridges and paper stock, so any change of these components usually requires R&R.

The Problem:
The High-Definition Multimedia Interface (HDMI) was developed to transmit graphics and audio signals for home entertainment systems and to enhance TV displays by using a slightly limited range of colors and more contrast. Since some computers and graphics cards also use HDMI ports, a full color range capability was also included in the HDMI driver that is installed on computers. Unfortunately, in those computer drivers, the limited color range is set to be used by default. Therefore, you may not be displaying a full range of colors, brightness and contrast if you use an HDMI port and an HDMI cable in the following ways:

Connect the graphics card in a desktop computer to a monitor, digital projector or TV.

Connect a built-in GPU in a desktop computer to a monitor, digital projector or TV.

Connect a laptop computer to a monitor, digital projector or TV.

The Solution:
To use the full color range, you must change some settings in the HDMI driver.

1. INTEL – If your computer has an Intel graphics card or an Intel processor (CPU) with built-in graphics capabilities, then the you need to download and install the Intel Graphics Command Center. The instructions for using the Intel Graphics Command Center to set the HDMI driver to use the full color range are here.

2. NVIDIA – If your computer has a graphics card with an NVIDIA GPU, or a built-in NVIDIA GPU chip, you need to download and install the NVIDIA CONTROL PANEL. This software is usually bundled together with the GPU driver and the two can be downloaded and installed together.

The following procedure sets the HDMI driver to use the full color range. Click the Windows start logo, navigate to the NVIDIA Control Panel, and click to run it. In the NVIDIA Control Panel window, expand the DISPLAY section (left) and select CHANGE RESOLUTION. In the APPLY THE FOLLOWING SETTINGS section (center), select USE NVIDIA COLOR SETTINGS, and set the following:
..Desktop color depth = highest,
..Output color format = RGB,
..Output color depth = 8bpc (if your GPU and monitor can display 10 bit color, set 10bpc),
..Output color range = Full,
Select APPLY (bottom right). Close the program.

3. AMD – If your computer has an AMD graphics card or an AMD processor (CPU) with built-in graphics capabilities, you need to download and install the AMD SETTINGS software along with the driver for your GPU.

The following procedure sets the HDMI driver to use the full color range. Right-click on the desktop and, in the pop-up menu, select AMD SETTINGS. In the AMD SETTINGS window, select DISPLAY (top). In the DISPLAY window, select PIXEL FORMAT, and select RGB 4:4:4 PIXEL FORMAT (Full RGB). Close the program.

4. MAC – The MAC OS provides color range settings in SYSTEMS SETTINGS > DISPLAYS. Accessing those settings is slightly different in various versions of the OS. For example, in Ventura 13, select the APPLE MENU > SYSTEM SETTINGS > DISPLAYS (right side bar). Click the name of the display connected to the computer with an HDMI cable. From the PRESETS menu, select one of the following color range options: Digital Cinema (P3-D65), Design & Print (P3-D50), Photography (P3-D65). P3 is an RGB color space developed by Apple Inc. for wide-gamut displays.

In earlier versions of the MAC OS, select SYSTEM PREFERENCES > DISPLAYS, which should open one DISPLAY window for each display connected to the computer. Each DISPLAY window should have a COLOR tab that lists the color ranges available on each display device. Select the DISPLAY P3 option.

Step 2: Set Color Spaces in Camera RAW, Lightroom & Photoshop

Color Spaces:
A color space is a subset of all the colors that human vision can perceive. The smallest subset, called the sRGB color space, is used to display color image files on the Web, phones, tablets and computer monitors, and is also used by most professional printers. Slightly larger subsets, the Adobe RGB and Apple Display P3 color spaces, contain more colors and are used by some mid-range & high-end computer monitors, digital printers and some professional printers. These color spaces were developed to improve photo editing and to display a slightly larger range of colors (gamut) compared to sRGB. A detailed comparison of sRGB, Adobe RGB and Apple DIsplay P3 can be found here. The largest color space, called ProPhoto RGB, developed by Kodak for photographers, includes almost all of the colors that humans can perceive. Currently, there are no devices that can display or print the ProPhoto RGB gamut. More details about color spaces are described here and in this video.

In photography, the camera usually assigns a color space to each jpg image, according to settings chosen in the camera’s menu. Each jpg image file has the code for a particular color space embedded into the file. RAW files, however, do not have a color space assigned to them or embedded into the file. After importing and processing a RAW file in a RAW file editor (e.g. Adobe Camera Raw, Lightroom), the product can be assigned a color space before being saved as an image file (e.g. TIFF, PSD, DNG, jpg, etc) or before being exported (as a TIFF or PSD file) to an image editor like Photoshop.

Color space codes are embedded into image files to instruct the OS, photo editing programs, slideshow programs and printers, etc. how to interpret the color data. Without the embedded color space code, the file is ‘untagged’ (not color managed) and the software has to guess how to display or print the color data, which may lead to a poor result.

Which Color Space Do I Use?
Practical advice about which color space to use when editing and saving images for various destinations is presented in this video.

Setting Color Spaces in Camera Raw, Lightroom & Photoshop:
This video explains how to properly set color spaces in Camera RAW, Lightroom and Photoshop. The specific instructions for Camera RAW begin at the 5:44 minute mark, Lightroom instructions begin at the 7:36 minute mark, and Photoshop instructions begin at the 0:51 minute mark.

A more advanced view of choosing and setting a color space in Photoshop is presented in this video. NOTE: In Photoshop, some color setting windows (ie Convert to Profile, Assign Profile) refer to color spaces as ‘profiles’.

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Color Management

Articles

Overview of Color Management

Monitor Calibration for Photography

Soft Proofing

Soft Proofing in Lightroom

Soft Proofing in Photoshop

Videos

Monitor Calibration Playlist (Calbrite/X-Rite). View all videos in the playlist that are appropriate for your equipment.

Monitor Calibration (Spyder)

Projector Calibration (Calbrite/X-Rite)

Printer Calibration (Calbrite/X-Rite)

Printer Calibration (Spyder)

Match Prints & Monitor (Calbrite/X-Rite)

Calibrate All Photography Devices (Calbrite/X-Rite)