Practical Guide to Color Spaces: How to Make Better Photos
Warm colored King Penguin chicks against a blue sky, South Georgia Island.
One of the things I learned, while migrating from an analogue to a digital photography workflow, was how to use the right color space to produce better photos.
Photographers use one of three RGB color spaces (ProPhoto RGB, Adobe RGB and sRGB) to map the colors in a scene into a color space that best fits the limitations of an output device and material. Commercial photographers also need to understand the printing industry preferred CMYK color space.
There are numerous ways to represent color and also to illustrate relationships between colors. This post deals specifically with the concept of color space for photographers.
Photography Color Wheel featuring RGB and CMYK color spaces.
Color Space For Photographers
As an initial introduction to color space in the world of photography it might be helpful to start with a general, overhead view prior to discussing the various RGB color spaces.
Let’s start with the basic differences between the RGB and CMYK color spaces.
The term RGB, refers to the three primary colors in photography.
Red
Green
Blue
RGB is the preferred color space of the photography industry and is favored by the following devices:
Still and video cameras
Scanners
Mobile phones and devices
TV and computer monitors
It’s worth noting that, in the world of photography, pure blue is neither aqua nor ultra marine. Pure blue is actually a very deep blue that equates to a hue (i.e., color) that’s almost violet.
In addition to primary colors photographers also need to understand their complimentary colors which we can define as follows:
Cyan
Magenta
Yellow
These three complimentary colors sit directly opposite their primary color counterparts on the color wheel.
In a world of duality it can be useful, therefore, to understand that opposites both oppose and compliment each other. Here’s some common examples from the world of color photography.
Red rose against a cyan colored sky
Magenta flower petals surrounded by green leaves
Yellow dress against a blue wall
Here’s how the primary and complimentary colors in photography relate to each other.
The CMKY Color Space
Commercial print houses print onto media that uses reflected light and ink to form an image. They utilize a subtractive method of printing referred to as the CMYK color space which can be defined as follows:
Cyan
Magenta
Yellow
blacK
CMYK is, therefore, the color space favored by the printing industry for the production of magazines, newspapers and brochures.
Take another look at the complimentary colors listed in the table above. You’ll notice that a fourth color, blacK, is added to the CMYK space.
The letter K in the CMYK color space refers to a special black plate that commercial print houses would traditionally add to the printing pack to produce a better quality black.
The letter K is said to stand for the word Key, but these days the letter K is probably more commonly taken as the last letter in the word blacK.
Back in the days of photographic plates it should have been possible, in theory, to produce black when aligning cyan, magenta and yellow plates of equal density together.
However, in practice, a dirty brown color was often produced.
As a consequence the Key or blacK printing plate was added to the stack to provide a good black and produce better shadow detail.
In the digital world it’s because of this extra blacK layer that a digital file grows in size when converting a three layer RGB file into the four layer CMYK color space.
Arrangement of color barrels in Ubud, Bali make for a great composition.
Different RGB Color Spaces
These days printing in color on inkjet printers is achieved via the use of cyan, magenta, yellow and black inks.
Nonetheless, most photographers adjust images on the desktop within one of the following RGB color spaces:
sRGB
Adobe RGB
ProPhoto RGB
sRGB is the smallest of these color spaces and is the native color space of images displayed on the world wide web. Examples of how we view images on the web include the following:
Email
Social Media
Blogs
Websites
Adobe RGB and ProPhoto RGB are significantly larger color spaces which many photographers prefer to work within on the desktop.
Once the image has been completed and saved a web friendly version can then be exported.
This would result in a significantly reduce file size, as defined by pixel dimensions, mapped into the smaller sRGB color space for reproduction on the web.
That’s precisely my workflow when preparing images for display on this blog. Here’s how it works.
I post process my images in Adobe Lightroom and Photoshop within the larger ProPhoto RGB color space.
Once completed I export a version of the file in the smaller sRGB color space and upload to my site for viewing on the web.
What about inkjet printing, whether done at home or by a professional lab or boutique printer like Matte Image in Melbourne, Australia?
In a properly calibrated and profiled workflow the resulting RGB numbers would be translated into the appropriate color space to ensure as accurate as possible color reproduction by the inkjet printer.
When files are to be output via a printing press the finished RGB files need to be converted into CMYK, either by the photographer or by the commercial printer, at the pre-press stage prior to printing.
The CMYK color space is the smallest of any of the color spaces discussed in this article.
Setting Color Space In Camera
There’s some debate as to the best option to set the color space to on a digital camera.
Frankly, if you photograph in RAW mode, it’s irrelevant as the color space is applied during post processing of the image in a RAW Converter like Adobe Lightroom or Adobe Camera RAW.
Most folks, however, photograph in JPEG (Joint Photographic Experts Group) mode and have the choice to select either sRGB or Adobe RGB in camera.
It’s actually a contensious issue.
On one hand you could argue that landscape photographers would benefit by recording their images into the larger Adobe RGB mode, particularly when photographing particularly colorful scenes.
On the other hand there’s an argument among some portrait photographers, labs and printers that to ensure skin color doesn’t become too colorful the smaller sRGB is the preferred option.
By all means consider advise based upon the kind of photography you do most often but, at the end of the day, choices are personal and it’s advisable to run tests before committing to a particular workflow.
Portrait of a shopkeeper in his tiny, colorful shop in Kolkata, India.
conclusion: How to Make Better Color Photos
Understanding the relationships between primary and complimentary colors is essential in producing photos that convey the mood, feeling and message you’re trying to communicate.
If you want to improve the composition in your photos start constructing your scene around the visual contrast that occurs between primary and complimentary colors.
If you’re looking to create dynamic portraits think about the colors your subject is wearing and consider placing them against a background that features a complimentary color.
While the shopkeeper I photographed in Kolkata was wearing a white tee-shirt his skin, and the produce surrounding him, had a lovely, warm tone which provided great color contrast with the richly blue painted wall behind him.
The same is true in landscape photography. Imagine how dynamic yellow sunflowers can look against a blue sky.
I hope this brief introduction to color spaces has provided you with some interesting reading and helped to clarify some of the information you may have read previously.
If color is important to you it makes sense to spend time expanding your understanding of color and how to work with it, both in camera and, if it’s appropriate, during post processing.
The posts listed below should prove to be very helpful resources.