Colour Space - A Clearer Understanding

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Colour Space | nickdjeremiah.com
Updated June 2016

IF YOU ARE A COMMERCIAL OR WEDDING PHOTOGRAPHER, THIS ARTICLE DOESN'T APPLY TO YOU.

Colour space is a strange subject, and for a lot of photographers, something that makes absolutely no sense what so ever. So I’m here to help you out with it. This isn’t so much a tutorial, but rather helpful information for your noggin. I'll start off by explaining some terminology and a visual representation of colour before getting into the nitty-gritty.

  • For 90% of you, you're better off working in a full sRGB workflow. I explain why later in this post.
  • If you're using a wide-gamut monitor, you need to be working in a full Adobe RGB (1998) workflow.

Overview

The following descriptions have been paraphrased from the Technicolor Colour Space website.

Gamut - A gamut is the range of colours that a device can capture or show.

Colour Space - A colour space is a predefined specification that defines a particular group of colours. A colour space is mapped into a device’s gamut so the device’s colours correspond to the real-world.

Colour Spaces

 





 

 

 

 

 

File Formats
 

Adobe RGB (1998) - For artists, Adobe created the Adobe RGB standard in 1998. While the blues and reds are identical to sRGB, this colour space accommodates more vibrant greens. If artists do their work in Adobe RGB, they must use expensive professional wide-gamut displays to accurately view their work.

sRGB - In 1996, the sRGB colour space was developed as a standard for display technologies. The majority of consumer monitors and displays output this colour space.

DCI-P3 - DCI-P3 refers to the colour space used in digital movie theatres and encompasses much more than sRGB. Hollywood films are provided to theatres in DCI-P3 in order to match the gamut of the digital projection equipment used.
 

RAW: A file format that is essentially the digital equivalent to film. RAW files don't take on any colour space data.

JPG: A file format that you could argue is the equivalent of a polaroid. Once you take the image, you can't do a real lot to it. JPGs store colour space data.


Visual Representations

Let's take a look at a visual representation of colour space. Most consumer displays can only output sRGB. Apple's 27" 5k iMac and 21.5" 4k iMac can output DCI-P3, and the professional wide gamut monitors made by Eizo and NEC output Adobe RGB (1998).

On the left, is a representation of the Adobe RGB colour space. Next to it you will see the DCI-P3 colour space. The white outline shows where Adobe RGB is in comparison. You can see that P3 is not quite wide-gamut but it's pretty close. It's actually 25% larger than sRGB.

Below, on the left, you can see the Adobe RGB colour space. This is the colour space that commercial and wedding photographers should be working in. On the right, you can see the sRGB colour space. The white outline shows the comparison between the two. sRGB is what all consumer computer monitors can display and what 90% of photographers should be using. If you're an event photographer, into family portraiture or newborns for example, there's no need to use a wider gamut as your clientele likely doesn't require it. Not to mention the need for an expensive wide-gamut monitor.

 
Please Note: Not all print labs print in Adobe RGB. Consult them before ordering prints.

The Nitty-Gritty

So  why  should  I  be  working  in  the  sRGB  colour  space?

For the majority of us, we aren’t editing on a professional monitor, one that can display the Adobe RGB (1998) colour space. These monitors are known as wide-gamut. Most of us are working on laptops, iMacs or standard monitors, all of which can only display the sRGB colour space. When editing, you're only seeing an sRGB version of your image because the monitor you are using can only display that colour space, and therefore you are making adjustments based on an sRGB rendering. If you were then to save that image in Adobe RGB and print in Adobe RGB, your prints won't look like your image on screen. You'll likely see more colours, but they'll potentially be over saturated.

The reason for this, is because your editor's working colour space may be set to Adobe RGB. When making adjustments to your images, all these changes are happening in a larger colour gamut than what your display can produce. So when you increase the saturation of the blues for example, they're actually being saturated more than what your display can show you.

If you shoot RAW this will be less of a problem. RAW images have no colour space and is assigned one once its in the editor. So even though you’re working in a smaller colour gamut (sRGB) you’re not doing any harm to the image. If you do need that larger colour space, you’ve still got it because you shot in RAW. Just change the colour settings in your editor to Adobe RGB and re-edit the colours in your image. If you’re working in Adobe RGB and convert to sRGB, then print in sRGB, your prints will look the same. But if you’re going to convert the colour space, you should work natively in it to begin with. It'll save you time, your colours will look nicer and you'll reduce your chances of colour banding (this can happen when colours are converted and squished into a smaller gamut).

If the average-joe client asks for an Adobe RGB image, it would be better to educate them on this matter. Unless they can actually reproduce that colour space, then they probably don't know what they're asking for. If your client is professional or commercial however, they'll need Adobe RGB. In this case, it'll be worth the investment to upgrade to a wide-gamut monitor. You don't want to risk providing them an image with wacky colours.

The only way to get an almost exact match with colour is if you’re editing in the same colour space as your monitor can display, and you're printing in the same colour space as you were working. Not to mention, web browsers can’t display Adobe RGB even if you’re using a wide-gamut monitor, so when you upload images to the web, they must be in sRGB regardless of what monitor you’re using. Otherwise your images will look muddy and the colour will be desaturated.

Always work in the largest colour space available
— every pro photographer ever
 

A lot of pros will tell you this, and they're absolutely right. But you can’t always see the largest colour space, so the edit you’re making can look very different. The in-gamut colours will look the same, but the out-of-gamut colours won’t. If you don’t know what they look like until you print, it's not a risk you want to take as it costs time and money. But what about soft proofing? Isn't that for this exact issue? Well, no. Soft proofing cannot show you out-of-gamut colours if you’re monitor can’t. Soft proofing is for seeing what your image will look like printed on a certain paper from a certain printer; it cannot show you what it looks like in a larger colour space. It can show you where the colours are clipping (going out-of-gamut) and this will give you the ability to edit further to fix those issues.

A native sRGB image will generally look better then an image converted to sRGB. So it’s best to work in the final output colour space from the beginning to get the best quality image, but only if you can see it.

I'm  a  commercial  or  wedding  photographer.  Should  I  be  using  Adobe  RGB?

Yes you should. Commercial photographers are working for commercial clients. So they're images will likely be displayed in magazines, billboards, posters and many other mediums that will use the Adobe RGB colour space. So you must be working in an Adobe RGB workflow from camera to print. If you're a wedding photographer, you should be getting fine art prints done at a pro lab, printing in Adobe RGB because the images will look 100 times better (please consult your printer about what colour space they print in before sending them images). If you're providing any client with digital files however, they'll need to be in the sRGB colour space because they'll only be able to view it that way.

Investing in a wide-gamut monitor is an absolute essential task and something you should start saving up for. I have linked an affordable one below for you to check out.


 

BENQ SW2700PT 27" MONITOR

$999AUD

This is an affordable, yet very high quality wide-gamut monitor. 


The ProPhoto RGB Myth

You may of heard of the ProPhoto RGB colour space, and you may of heard a lot of 'professional' photographers touting that you should be using it because it's "The largest colour space and you should be working with all the colours". This is total nonsense. The ProPhoto RGB colour space encompasses such a large colour gamut that it actually falls out of the visible colour spectrum of our eyes. Those colours are known as theoretical colours because we can't see them, we assume that's what they look like. Photography is all about seeing, and making sure your images are colour accurate is extremely vital. So why would we use a colour space that includes colours we can't see? Exactly... We wouldn't. And you shouldn't.

Visible Colour Spectrum | nickdjeremiah.com

But that's not the only reason. There are colours in ProPhoto that we can see, and these colours are far and above the gamut of Adobe RGB. However, there isn't a monitor or printer available that can print above the Adobe RGB gamut. Even though we can see part of ProPhoto, we can't reproduce it, which leads me to ask, why would we use a colour space we can't reproduce? Exactly... We wouldn't. And you shouldn't.

To the right is a graph. It is showing five colour gamuts. LAB (the horseshoe shape), ProPhoto RGB, Adobe RGB, sRGB and CMYK. LAB is approximately the gamut of the human eyesight. You can see that ProPhoto's triangle goes beyond LAB in the greens and the magentas. These colours don't exist. Or at least we can't see them and never will, so they might as well not exist.

With all that said and done. Don't use ProPhoto RGB. You can't see it, you can't reproduce it, so why would you use it.

 

I hope this has helped clear some confusion about colour space. If it has, click the like button below to let me know. If you have any questions, comment below, I'm more than happy to help you out.