Ermal Alibali


Color Spaces
in Photography

Understandig Color Spaces is important in photography. The most well-known color spaces are sRGB, Adobe RGB, and ProPhoto RGB. In this post I want to introduce you to ‘color spaces’ and when to use them.

1. Color Space

“Color space” just means a set of colors, a section of colors. sRGB, Adobe RGB, and ProPhoto RGB are three of the most commonly used in photography and RGB stands for Red, Green, and Blue.

As a photographer you had already seen this illustration before:

Color SpaceThe diagram represents every color our eyes can see. So, sRGB, Adobe RGB, and ProPhoto RGB fit into this diagram. How? See the following diagram with the color spaces:

Color Spaces

Let’s analyze them:

sRGB is the smallest color space. The range (or gamut) only covers apart, a ‘space’, of this color diagram.

Adobe RGB gamut is larger.

ProPhoto RGB is the largest and it includes “colors” outside what our eyes can see (imagination colors). It includes also sRGB and Adobe RGB.

But keep in mind that these coordinates are specific to each color space. The same values won’t result in the same color in both sRGB and Adobe RGB, for example.

2. Bit Depth

The Bit depths are simply how many bits of data are used to create each pixel.

The baseline in photography is usually 8 bits per pixel, meaning that each individual pixel can represent 256 colors. So in your camera, there are 256 shades of red, 256 shades of green, and 256 shades of blue. The total is 256 x 256 x 256, or a whopping 16,777,216 RGB values.

When we talk about a 16 bit per channel, it means that are 281 trillion RGB values. It is important to work and use 16-bit color while you’re editing a photo because it makes gradients in an image as smooth as possible.

As we see in the diagrams, ProPhoto has “more colors” than others so we can think that using ProPhoto color space gives us more colors. It’s wrong! ProPhoto RGB may be “bigger” in terms of range, but an image in ProPhoto RGB color space doesn’t have more colors than a photo in sRGB. The important parameter is the bit depth. An 8-bit photo is limited to about 16.8 million RGB values, no matter what color space it’s in.

A larger color space means you work with higher bit depth photos. Hight bit depth prevents banding in photos and gradients result in more uniform and smooth than a lower bit depth. For example in sRGB color space using 8-bit per channel color will often result in smooth gradients that are good, with no perceptible banding.

3. Working Space & Output Space

Gamma Color Space

There are two stages along the photo pipeline where you need to choose a color space: post-processing and outputting your image.

When you post-process a photo, in general, it is ideal that your working space is ProPhoto RGB when you edit a RAW photo. RAW photos often contain colors outside of both sRGB and Adobe RGB color spaces, especially in high-saturation shadow regions. If your photo’s working space is sRGB, you’ll clip any colors that fall outside the sRGB range.

Lightroom doesn’t even let you specify sRGB as your working space for this reason.

Photoshop’s ideal settings are a bit tricky, but if you’re unsure, just set Edit > Color Settings > RGB > Preserve Embedded Profiles. 

That way, you preserve the color space of the photo.

A lot of photographers use software like Adobe Camera RAW or Lightroom then open the image in Photoshop. But their export settings may create images in sRGB or Adobe RGB working space.

To avoid it click on the blue link at the bottom of Camera RAW and change the images to ProPhoto, 16-bit.

In Lightroom, go to Lightroom > External Editing > File Format TIFF, Color Space ProPhoto, Bit Depth 16.

If you just realized that you’ve been using sRGB or AdobeRGB for Camera RAW’s or Lightroom’s external editing settings, and you’re rushing to change it to ProPhoto remember you now have an extra step to do when exporting images from Photoshop. For the web you have to convert them in sRGB. Click on Edit > Convert to Profile > sRGB. 

Remember that converting to sRGB for web images is essential.

Let’s talk about Output space. It is the color space chosen for your final photo. The ideal color space depends on your output medium.

For the web, sRGB is generally ideal.

To send files for other photographers to edit, perhaps ProPhoto is preferable.

When you edit an image in ProPhoto, you minimize the risk of clipping colors unnecessarily. If you have clients, they’ll open the images on some old photo viewing program without color management. This is why you have to export in sRGB.

For printing, converting directly from a large working space (like ProPhoto) to the printer’s specific color space is ideal. Some (low-end) print labs won’t accept photos in any color space other than sRGB or perhaps Adobe RGB. In that case, send what they request, or switch to a different printing service lab.

If you print your photos and have a wide-gamut monitor use Adobe RGB. It’s the best way to get your print to match the image on your screen.

4. How to print a photo

If you’re not well-practiced at printing, the best thing to do is simple: Send your images off to a lab of your choice and pick their “color correction” option if they have one. For advanced printing needs, you’ll have to decide between printing at home or sending it off to a higher-end lab (one that lets you do the corrections yourself).

If you’re sending it off to a lab, download their ICC profile for the ink/paper you’re using. Make your edits to exactly how the print will look. Export the image in a large color space (ProPhoto for example), then convert to the printer’s ICC profile. Send it off to the lab and specify no color corrections.

For self-printing, do the same thing, just using the print module in Photoshop or similar.

5. Print vs Screen

No matter how good your display is, there are colors in ProPhoto that your monitor will not show. This means that you are editing colors that you can’t actually see on your screen.

In photography, it just means that saturated shadows have more detail and nuance than your monitor can display. If you want that detail and nuance to show up in a print, follow the steps above.

If you want the print to match the screen convert the photo from your working space to the color space that resembles your monitor. Adobe RGB if you’re using a wide-gamut monitor, and sRGB if you’re using a typical monitor. Make adjustments if needed, then print. You’ll get a print that more closely matches the screen.

6. The importance of calibrating and profiling your monitor’s display

Calibrating your monitor is an important part of post-processing. You know that every viewer with an uncalibrated monitor will see your photos differently.

Calibration and profiling are important in order to get your print to match your screen as much as possible.

I show you how I calibrated my monitors using the Datacolor SpyderX Pro and why it is important to do this especially if you work with colors as a photographer, videomaker, graphic designer, visual artist…

7. Conclusion

That’s it! Many photographers have no idea when to use sRGB, Adobe RGB, or ProPhoto RGB. Now you are ready. That should help you avoid two of the cardinal sins of color spaces: clipping colors unnecessarily, and publishing photos with the wrong color space.

If you have any questions contact me directly or on social networks and I will help you!

Latest Articles: