Getting “It” Right For Better Photographs: Color Space

What do I mean by “color space” and why should you care?

Your monitor is the primary device you rely on to show you the colors of your photographs or other artwork on your computer. Today’s monitors are primarily flat screens and may use various technologies for displaying images (this sounds suspiciously like the beginning of the last “Getting ‘It’ Right” entry, doesn’t it?).

The color space, in fairly simple terms, is how many colors are available and how many can actually be shown on the monitor or the printed image.

Your eye can see billions of colors but a typical 8-bit image can contain 2⁸ colors per each of the three channels, or a maximum of 16.7 million colors. That’s a lot of colors. I don’t want to get into a deep discussion on color theory because I’d like to keep this on a basic level.

The bad news is that a typical 8-bit monitor can’t see anywhere near 16.7 million colors. Nor can a typical inkjet printer reproduce them. Although a good printer can reproduce more colors than a monitor, the colors are different.

Let’s talk about monitors for a minute…

Back in the olden days when color specs were being defined, a standard called “sRGB” was created to cover what could be reproduced on monitors of the day. This was (and still is) the standard for image viewing on monitors and the internet. An sRGB image should look the same (or at least similar) on monitors that are correctly profiled. This should be true in most applications and all web browsers without any need for additional color management. sRGB color space is also used for many digital cameras (when creating jpeg images) and is required by many print labs using chemicals to process their images.

In the late 90s, Adobe came up with a new standard that expanded the color space to include what could be reproduced on more up-to-date monitors and the better color inkjet printers. They called this “Adobe RGB(1998)”. This is still the color space of choice today for most commercial and fine art inkjet printing. Some of today’s 10-bit and higher monitors can display most, if not all of this color space.

Today, some people use an even larger color space called “ProPhoto.” However, you can’t see all of the ProPhoto colors on any printer or on most monitors (maybe on a 32-bit monitor, but there aren’t very many of those and I don’t know anyone who can afford one).

By the way, most good digital cameras will produce jpeg images using either Adobe RGB(1998) or sRGB. My preference is to shoot RAW and to apply the color space I need to use for each image on an “as-required” basis.

Knowing this, and hopefully not too confused, let’s try to simplify the process. If you stick to the following rules, you’ll be okay.

If your aim is to make prints on a giclée or inkjet printer - use Adobe RGB(1998) for your working color space. Do not use Adobe RGB(1998) for the internet - your images will look horrible (or at the least different from what you intend). This is because of how sRGB interprets colors that are not within its gamut (or range of colors).

If you are going to use the images for Powerpoint or similar presentations, on the internet, or for printing at a color lab - use sRGB. You can use sRGB for images you’ll be printing on an inkjet printer but they might not look as good as those you’ve printed based on Adobe RGB(1998).

What about ProPhoto? Well, for right now I just want you to be aware that it exists.

How do you specify the color space? In Photoshop, go to ”Edit > Color Settings...” and set your RGB color space preference. Photoshop will ask you what it should do when you try to open an image with a different color space.

How do you change an image’s color space? In Photoshop, go to “Edit > Convert To Profile...” and chose your new color space. Photoshop’s “Save For Web & Devices” also has a check box for converting to sRGB since that action is intended for images destined for the internet.

Oh, by the way, you can convert from a larger color space to a smaller one as needed (Adobe RGB(1998) to sRGB). But you can’t go the other way and expect to pick up any of the colors in the larger color space.

Our next step will be to learn about “printer profiles” and how to use them. It’s really not as intimidating as it sounds and we’ll cover it next time.

You can add your comments and questions below.  I’ll be happy to answer them. The idea is to just enjoy and learn.