Silly Dog Studios LLC Daniel J Gregory Photography November 2, 2018 COLOR MANAGEMENT The holy grail of photography might not be a great location or decisive moment, it might just be getting a color to match from screen to screen and print to print. And, while it might be possible to get consistent prints without color management, I would say that the odds of winning the lottery while being eaten by a bear wearing a shark suit are higher. Without color management, we don t have a way to maintain consistent, repeatable, and known color values. Good as color management doesn t mean that you will just click and done, but the process is much easier now than in the past. At a basic level, color management is about describing a color, measuring color, and converting color. Sure, there is still work work necessary to get the computer s color management properly set up, learning how to deal with the difference between transmissive light and reflective light, color temperature of the viewing lights, issues with metamerism, and a host of other issues are important to get reliable color, with just a few steps, you can get a good color managed system setup. Don t let all the variables scare you off: it isn t as hard as it sounds. Properly calibrated color management systems do an amazing job of being able to show or simulate what will happen when we edit, print and share your work. Once we break it down, it really isn t that bad. NW Council of Camera Clubs 2018 Conference 1
How we understand color Color is one of the ways we experience the world. Yet for as much color as we see, we aren t really the best at judging and understanding color. Part of the reason for that is the way our eyes are created and also the differences between cultural, societal, and personal experiences with color. Depending on who you ask humans can see 3-5 million colors (200 colors at 500 levels of brightness and 20 levels of saturation), but some estimates are as high as 10 million. When you consider that your monitor can mathematically display millions of more colors than we supposedly see, you can start to see why color management become important. Our color perception is achromatic (grayscale) and chromatic (hues). In our eyes are rods and cones which each service a function to help us with grayscale and chromatic vision. The rods in your eye sensitive to light but not color (~120 million of them). The high number of these allow us to see details really well but mostly in well-lit conditions. Our cones are sensitive to color (~6-7 million). Cones are sensitive to various wavelengths (400-700nm), and our luma systems are basically B+(R+G) One of the biggest challenges of working with color is how do we describe a color. Because of the psychology and physiology required to see color, it is unlikely that there is uniformity in color perceptions, but there is some uniformity and agreement in understanding color. One of the biggest challenges of working with color is describing a color. Is something yellow, yellowish, yellow-green, banana yellow, etc. All of the variances of tints (color mixed with white), tones (color mixed with gray), and shades (color mixed with black) add to the complexity of how we see and identify a color. NW Council of Camera Clubs 2018 Conference 2
Working digitally, we can take all of these variables and break them down into their essential components to describe a single color. Each color is made up of a hue (color), saturation (purity of color) and luminosity or brightness of the color. By using these three variables, we can use them as a foundation of getting accurate color in our workflows. Color theories Many theories have been postulated to explain how we see and understand color. While not directly related to setting up a color managed workflow, they are critical to understanding how we see and experience color. But before we jump into some color theory, there are some general assumptions about how we see and experience color we should discuss first. Warm colors (red, orange, yellow) tend to appear to be nearer than cool colors (blue, green, cyan). Saturated colors appear nearer than desaturated colors Colors are most easily understood when next to a secondary color that modifies the first color. Which is the real yellow? NW Council of Camera Clubs 2018 Conference 3
Some basic color theory concepts Our visual memory is poor. Sensory memory is best for smell, taste, auditory, then sight, and finally touch. It is hard for us to remember colors and how they related to each other once we are no longer in front of the color or environment. Can you really remember the exact hue, saturation and luminosity of a strawberry you saw three years ago or is it a more general color knowledge of what red the berry should be? Since color is based on association (memory, likes, color relationships, etc.), these associations build in preference bias for specific colors. Originally color theories were solely based on several of the traditional sciences (physics, mathematics, biology, and chemistry) but now most modern theories include psychology and sociology aspects. Color can be effectively used and evaluated without a real understanding of color theory. We are inundated with so much imagery and color that we develop a sense of what works and doesn t work even if we don't necessarily understand why. At a most basic level color theory is based around how a small set of colors (usually three) can be mixed to produce all colors. Finally, color wheels can be used to explain color and color relationships, but it is important to note that painters wheels and photographer wheels are different because of how RGB light works verse mixing of paints and pigments. Local verse accidental color and duration effects Local color is the color we associate to objects under normal daylight. It is what we would generally say is the real color of an object or surface. However, light sources also have a color, and when that color hits the surface of an object and modifies how we perceive the color, we call that color an accidental color. In working with color we try to understand the difference between local and accidental. Because our color perception is time-bound, the longer we look at an image, the more color discriminations we can make. We can also train our eye to overcome local color/surface color to get closer to truthful color. NW Council of Camera Clubs 2018 Conference 4
Our eyes become less sensitive to minor color shifts, tints and tones after concentrated efforts. Moving our eyes to a new color environment helps reset the eyes ability to determine colors. Although we are more initially attracted to bright colors, the color complexity and balance of colors often produce more lasting and pleasing viewing experience over bright colors in the long run. Color harmony Colors in combination or relationship to each other that create a pleasing effect are called harmonious. This effect is analogous to musical harmony. Music in harmony is more pleasing than non-harmonious. When colors do not exist in harmony, they can create a negative reaction but that might be bound by not just the colors but also based on gender, age, race, religion, and other factors. It isn t always possible to know what colors will be universally accepted. While many color theories state colors on opposite sides wheel are in contrast and create harmony at the same time, you can t always count on the impact based on the biases noted above. These color harmonies can be simple or complex based on the relationship location of the colors to each other COLOR MANAGEMENT AND THE DIGITAL WORKFLOW The color management system is about making sure that from one device to another the colors that are utilized are precisely known and translated between devices. When working with known colors, we can then ensure that the translation from one device to another is as accurate as possible. In the end, most photographers don t care if the sky you photograph is R:45. G:46, B:167 to your monitor and R:67, G;89, b:123 to your printer. Photographers only care that the colors are the same or are relationally the same. This translation is similar to going to a restaurant with spicy food. When you place your order, you are asked how hot from zero to five stars. Of course, you have no real idea what three stars really means. Three stars to you may mean one to the chef. Color management is all about making sure that your three-star order comes out how you want and not too hot or bland no matter what the chef thinks of the spicy levels. To work in a properly managed workflow, three things must be present: NW Council of Camera Clubs 2018 Conference 5
1. Each device needs a description of what it can and can t reproduce concerning color. 2. These colors must be mapped to a common set of reference colors such as CIEL*a*b* or CIE xy 3. The color management system must be able to translate the colors of the device using the reference map to the correct corresponding colors. Working with profiles All of this work to make sure that one device can speak to another is done by the computer s color management system through the use of color profiles and color spaces. There are three basic types of color profiles. Most profiles are ICC profiles. The International Color Consortium for which the ICC profiles are named is a group of companies that created and maintain the open platform that we use for color management. The three basic profile types are: Input profiles are used to describe the colors that are defined by the capture device, such as a camera or scanner, and how those colors are converted into a standard color space like CIE L*a*b*. Display profiles are used to describe the colors of your monitors. A display profile is created with a color management monitor calibration tool. To create a display profile, you need a piece of hardware that is used in combination with software to create the proper profile for your monitor. The two most commonly used companies are X-Rite with their i1 or Colormunki line and Datacolor s Spyder product line. Output profiles are used to describe the colors of your printer and paper combination or another output device. These profiles are provided by the manufacturer, or you can custom build your own profiles by using a paper profiling device and software from a company like X-Rite or Datacolor. We also have a number of working color space profiles. Working color spaces such as srgb, Adobe RGB (1998), or ProPhoto RGB are profiles that have been accepted as standards across devices. When we are in Lightroom or Photoshop, we use these color spaces to describe the colors that are available to use while editing the image. Display calibration notes One of the most significant issues I see happen when people are printing is that their prints are too dark. This is usually caused by the monitor not being calibrated correctly. You want to make sure that the brightness of the monitor is turned down. For most people, I recommend between 80 and 100 lumens. You can set your monitor's white point to native, D50 or D65 as your white point. For most people, I recommend that you use D65 makes the most sense because of the color of the papers leaning towards blue. The D65 setting helps make the screen values appear more consistent to the paper. In my own setup, I use D65 with lumens of 90. Both those value are determined by my editing environment. You will need to do a little testing to figure out what values work for you, but the calibration software will help you set the corrected values. NW Council of Camera Clubs 2018 Conference 6
Gamut Each profile type has a specific gamut. Gamut is the amount or volume of color that can be represented by the device. When an image has colors that exceed the range and volume of the device, we call that being out of gamut. The ICC developed some ways to deal with colors that need to be shifted in the conversion process when images or colors are out of gamut or changing color spaces. The conversion process is handled by the rendering intent. Rendering intent Rendering intents are used to tell the color management system how to translate and convert colors from one color space to another. This process is essential not just for out-of-gamut colors but also for in-gamut colors when converting from larger color spaces such as Pro Photo RGB to smaller color spaces such as srgb. There are four rendering intents. For our purposes, we will focus on the two used by photographers, called relative and perceptual: Relative. This is my default rendering intent. This rendering intent is used for images where brightness values need to remain consistent, and colors are more natural in value. Colors that are shifted in this intent are clipped to the nearest reproducible color in the color space. This is best for images that have mostly in-gamut colors, colors brightness values for ingamut colors or for black and white images. You may get less-saturated colors from out of gamut colors, but more saturated colors from in-gamut colors than with the perceptual rendering intent. Perceptual. This rendering intent will maintain the relationships of out-of-gamut colors to preserve the color relationships by shifting in-gamut colors. This is at the cost of color fidelity and luminosity shifts. You can offset these, but they are likely to occur with this option. This option is best used with highly saturated images when the relationship of the colors is critical, or with images with colors that are more out of gamut. You are more likely to see artifacts such as posterization develop with this rendering intent. NW Council of Camera Clubs 2018 Conference 7
Two other rendering intents are used to translate color but not generally used for photography. They have specific uses and in some cases and help provide some accurate translations in design and production work. Saturation. This rendering intent is similar to perceptual. It attempts to shrink the color to maintain their respective relationship, but it will shift the hue of a color to preserve the saturation of the color. Used when moving to a larger color space or where color purity is required. Absolute Colorimetric. This intent is similar to the relative in that it holds in-gamut colors and clips out of gamut, but it differs in how it relates the color to the white point of the color space. Absolute holds the white point of the original space in the conversion rather than allowing the white point to shift like it does in the relative intent. Color management in Photoshop There are a lot of options for setting up color management in Photoshop, and because there are so many options, it is easy to get sideways. For my setup, I set up a few key options to make my workflow as easy as possible, and I try not to get lost in the weeds. To get to the color management settings in Photoshop, select Color Settings from the Edit menu. In the screen capture above, you can see the settings that I use. I want to make sure that my Working Spaces boxes are set up correctly. For RGB, I use ProPhoto RGB, because I want the largest color space to work with on my images. My Gray value is set to Gray Gamma 1.8. The gray space should be set to match the RGB color space that you are using. ProPhoto uses a Gamma NW Council of Camera Clubs 2018 Conference 8
Gray of 1.8. Adobe RGB (1998) uses a gamma gray of 2.2. The srgb should be set to Gamma Gray 2.2, although it is technically not Gamma Gray 2.2 but a slight modification of Gamma Gray 2.2. The Gray profile is used to render black and white and brightness of the mid tones. Under Conversion Options, I set my Intent to Relative Colorimetric, and I also make sure to check the boxes about profile mismatches so that I am warned when opening files or images that are outside my default color settings. Under Color Management Policies, I make a few changes from the defaults. This section is all about what Photoshop should do when there is a profile mismatch or profile issue. When you are working with files that have mismatched profiles, it is easy to get confused about which option to select. In many cases, you will want to use the embedded profile because that is what the intended profile was when you received the file. But there are times when you will want to change the profile of the image. When you select Assign profile, Photoshop keeps the numbers and changes the color s appearance. This option is used most often when a profile is missing. Convert to Profile allows you to keep the color appearance but the number assigned to the color changes. In nearly every case, I want to Convert to Profile with my photographs so that the color s appearance remains accurate. Lightroom Color Management Lightroom has a built in default settings for color management, so you don t have to worry about setting up any color management settings. They are always on. In the Development module, it is using a variation of ProPhoto with a srgb tone curve applied called MelissaRGB. For all intentisve purposes it is ProPhoto. In the Library, Book, Slideshow, Map and Print modules the screen display in AdobeRGB. NW Council of Camera Clubs 2018 Conference 9
When you print, the color management engine in Lightroom will translate the images, based on the rendering intent, into the correct color space selected in the managed by printer or use the following ICC profile option. Color space and sizes A color space is a conceptual model to understand how a device creates, renders and uses color. There are device-dependent, device-independent, and working spaces. Devices that can show large amounts of color are considered wide-gamut devices. When working digitally, our files are translated into a standardized working space such as AdobeRGB, ProPhoto or srgb. It s important to think about the difference in color gamut between the color spaces and think about why you would want to work in a given working space. The chart below shows the relative sizes between srgb, Adobe RGB (1998), and ProPhoto RGB. In the image on the largest continuous color block is Pro Photo RGB, and the wireframe is Adobe RGB (1998), and srgb is the reddish color block in the center. As you can see, the Pro Photo RGB space is considerably larger than the other spaces. The Pro Photo RGB space is extremely close, and some cases exceed normal human color perception. For my photographs, I want to use the largest color space I can, so I default to Pro Photo RGB. There NW Council of Camera Clubs 2018 Conference 10
are some cases when you might want to work in Adobe RGB (1998) or srgb. In some cases, skin tones render better in AdobeRGB (1998), and there are some alternative processes digital negatives that are printed in Adobe RGB (1998). But, for the most part, I want that Pro Photo RGB color volume. Why ProPhoto by default? The reason that I use ProPhoto by default is two-fold. One I want to make sure I work with the largest space possible. The second is about future proofing. If you go back at look at monitors and printers from 10 years ago, they couldn't show or display the AdobeRGB color space, but now many of those devices now exceed the Adobe RGB color space. By using ProPhoto, I am hopefully providing some level of insurance that I can continue to get access to those colors. The tradeoff is that sometimes I have to print my images to see the actual colors, but I am ok with that trade-off. NW Council of Camera Clubs 2018 Conference 11
Daniel J Gregory Photographer / Photo Educator daniel@danieljgregory.com Workshops and resources www.danieljgregory.com www.sillydogstudios.art Social Media @dangregphoto Podcast On itunes, Spotify, Google Play The Perceptive Photographer NW Council of Camera Clubs 2018 Conference 12