Color profiles

Learning goal

You will be able to explain why a photo can look different on different screens and in print, and prepare your file for where it is going. You will define a color space as the limit of the colors a file can use; you will know the difference between sRGB and Adobe RGB and which one is safe where; you will see why embedding a color profile in a file matters; you will understand how your screen's brightness and calibration affect your editing decisions; and by checking a photo on several screens before sharing it, you will catch how light or dark skin can shift on different screens.

The question

At a weaver's loom, you are photographing a new flat-woven rug woven in turquoise and madder red, and the woman who wove it. When you edit it on your computer, the colors are exactly as they should be: the turquoise deep, the red warm, the woman's face in its own color. You upload the photo to a social network, then look at it on your phone. The turquoise has faded, the red has turned brick colored, and the woman's face has grayed a little.

Why does my photo look different on a phone? Because the numbers inside a file don't describe a color on their own; they also need a piece of information saying by which color scale those numbers should be read. In this lesson we will talk about color spaces, color profiles, and what to watch for so that colors don't get lost on the way as you carry a photo from screen to screen and from screen to print.

Context

Throughout this module we managed color in the light, in the camera and in editing: we set white balance, read color relationships, and warmed and cooled frames while protecting skin. All these decisions are in the end written into a file, and that file is seen by someone else, on another screen or on paper. The module's last lesson deals with the last stop of this journey.

A screen, a printer or a phone produces colors with its own capabilities. Some can show more saturated reds, some deeper greens; some work brighter, some dimmer. Color profiles are a translation system built so that these different devices show the same file as much the same way as possible. The system only works when it is used correctly.

Simple explanation

What is a color space?

A digital photo stores the color of each pixel with three numbers, for red, green and blue. But how saturated a red the number for "the most saturated red" really corresponds to depends on which color space the file is in. A color space is a scale that defines which colors in the world these numbers match. The whole set of colors a color space can cover is called its color gamut.

There is no screen or printer that covers all the colors the human eye can see; each color space covers part of this wide area. A wide color space can store more saturated colors, while a narrow color space stops at a less saturated limit. A color that doesn't fit into a narrow space is pulled inside the limit when it is converted; in the process its saturation drops or its tone shifts a little.

What is the difference between sRGB and Adobe RGB?

sRGB is a relatively narrow color space that has long been the shared language of the internet and of screens. Most browsers, apps and phones count a file as sRGB when they find no profile in it. That is why sRGB is the safest choice for a photo to be shared on the internet, sent by message or shown in a presentation: whatever device the person opening the file uses, the colors look largely as expected.

Adobe RGB is a wider color space; it can store colors that spill outside sRGB, especially in greens and turquoise-cyan tones. This difference can show in prints made with good printers. But if an Adobe RGB file is opened in an app that doesn't do color management, or opened having lost its profile, the colors look faded and dull; the fading of the rug's turquoise is a typical example of this. Many new phone and computer screens can also work in a color space wider than sRGB; that is why the same file can look vivid on one device and flatter on another.

How do profiles and RAW work?

A color profile is a small piece of information saying which color space a file is in, and it can be embedded inside the file. When the profile is embedded, a program that does color management reads the numbers correctly and translates them for its own screen. If the profile isn't embedded, the program makes a guess, and if the guess is wrong, the colors shift. That is why it matters to make sure, when exporting a photo, that the option to embed the profile is on.

Your camera may have a setting called sRGB or Adobe RGB. This setting only affects the JPEG files the camera produces. RAW isn't tied to a particular color space; you choose the color space when exporting from the editing program. A practical way is this: shoot RAW, do the editing in a wide space, and export the file as sRGB for the internet, and for print with the profile the place doing the printing asks for. Asking the print shop which profile and which file format they want prevents most of the surprises that come later.

How do you check the screen and skin?

The screen you edit on is the referee of all your color and tone decisions. If the screen is too bright, you edit photos darker than they should be and prints come out dark; if the screen has shifted toward a cool or warm color, you add a color in the opposite direction in editing. Monitor calibration is the work of bringing a screen's color and brightness to a known standard with a measuring device. Even if you don't have the device, lowering the screen's brightness to a reasonable level for the room's light, and turning off color-changing settings such as night mode while editing, makes a big difference.

Skins are the most easily noticed colors on this journey. Dark skin can lose its detail along with the shadows on a dim or low-quality screen; light skin can slip into white on a very bright phone screen. Saturated orange and red tones can be squeezed a little when converted to a narrow space, and the face can shift slightly. Before sharing an important photo, opening it on a phone, a computer and if possible a tablet and looking at the faces is the simplest way to see whether everyone looks their own color.

Visual evidence

You go back to the photo of the weaver. When you open the file in the editing program and look at the export settings, you see that it was saved as Adobe RGB and without an embedded profile. The social network and your phone took the profileless file for sRGB and read the numbers on a narrow scale; that is why the turquoise faded.

This time you export the same photo converted to sRGB and with the profile embedded. On the phone the turquoise is deep again, the madder red warm again. The dark-skinned weaver's face, including her cheek in shadow, is in her own brown; her fingers reaching for the loom's threads and the lines on her forehead can be made out. For print, on the other hand, you ask which profile the print shop wants, lower the screen brightness, check the photo once more, and then send the file. The same photo; what changed was writing into the file by which scale the numbers should be read.

Common mistakes

Summary

The color numbers in a file turn into the right color only if it is known by which color space they should be read; the whole set of colors a color space covers is called its color gamut. sRGB is a safe, narrow space for the internet and screens; Adobe RGB is wider and can make a difference in print, but looks faded in the wrong place. Embedding the profile in the file, shooting RAW and exporting for the destination, and editing at a reasonable brightness, on a calibrated screen if possible, keep colors safe on the way; whether faces of every skin stay in their own color is checked on several screens before sharing.

Mini assignment

In this assignment you will experiment with color profiles and complete the module project.

1. Export the same photo once as sRGB and once as Adobe RGB; open both in a browser and on your phone and compare the difference.
2. Find the option to embed the profile in the export settings and make sure it is on.
3. Lower your screen's brightness and look again at a photo you edited before; does its brightness still look right?
4. Module project "One Color": shoot a series of six frames where a single color dominates. Use white balance, color relationships and the feeling of color consciously; in frames with people in them, protect the skin, and export the series as sRGB and check it on several screens.

Check yourself

• Did you see a difference on the phone between the sRGB and Adobe RGB files?
• When you lowered the screen brightness, did your earlier editing look different to you?
• Do the six frames of the "One Color" series carry the same color on several screens too, and do the faces, on every skin, stay in their own color?

Glossary

Mini quiz

1. Which color space is safest for a photo to be shared on the internet?

• A) Adobe RGB
• B) sRGB
• C) No color space
• D) It doesn't matter which

2. Why does an Adobe RGB file without an embedded profile look faded in many apps?

• A) The app counts the file as sRGB and reads the numbers on a narrow scale
• B) Adobe RGB always records colors faded
• C) The file is corrupted
• D) The phone's white balance is wrong

3. Which files does the camera's sRGB/Adobe RGB setting affect?

• A) Both RAW files and JPEGs
• B) Only RAW files
• C) No files
• D) Only the JPEGs the camera produces

4. What do you do before sharing a portrait of a dark-skinned person, to keep the face's detail?

• A) Check the photo only on your own screen
• B) Pull saturation to the highest
• C) Open the photo on several different screens and look at the detail of the face in shadow
• D) Save the file without a profile

Answers

1. B — Most apps count a profileless file as sRGB, and most screens can show this space.
2. A — Without a profile, the numbers are read on the wrong scale; saturated colors in the wide space look faded on a narrow scale.
3. D — RAW isn't tied to a color space; the space is chosen when exporting.
4. C — On dim or low-quality screens, the shadow of dark skin can lose its detail; checking on several screens shows this.

Summary card

• Color numbers don't turn into the right color without knowing the color space.
• Web and screens: sRGB; print: the profile the print shop asks for.
• Always embed the profile in the file.
• Shoot RAW, choose the space when exporting.
• Edit at a reasonable brightness; before sharing, look at faces on several screens.

Bridge to the next lesson

The color and tone module began with the color of light and ended with a file reaching another screen. Now we turn our attention to the glass in front of the camera. Imagine photographing the same rug and the same weaver once with a wide angle and once from far away with a narrow angle: both the world that enters the frame and the relationship between the face and the background change. What exactly do numbers like 24, 50 or 200 written on lenses describe? The next lesson talks about focal length and how it decides the angle of view.