Color Spaces – Color for Man & Machine

Part of a series – Color Managed Workflow

Today – Intro to seeing and describing color

.

When it is said that something is red

Exactly what does that mean (to you?)?

To a Physicist? To a piece of hardware? 

When we want a monitor to display red

How do we “tell it” what we mean by red?

When a monitor displays “your vision of red

How do we get a printer to match it?

How do we get everything to

Speak a common language? RED

.

Short answer – It’s all magic 😉

Or – There’s Maxwell’s Equations (seriously, they explain light)

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Long answer (for masochists), read my posts in this series

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All of the above questions basically assume that

What our camera captures for red (or any other color)

Agrees with what our eyes see

We’ll revisit the camera’s role in a later post

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A bit of trivia before moving on:

There is NO color, as we perceive it, until

A portion of the electromagnetic spectrum

The portion with wavelengths of 620 – 750 nm for red

(Note the relatively broad spectrum range)

Enters our eyes

Even then everyone’s eyes don’t “see” the same color

and dogs see only gray tones

In the end, it’s our vision system that creates the color we see

Not all vision systems are the same

Did you take the color test?

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Color Spaces:

Device Working Spaces

Software Editing Spaces

1. A digital dark room deals with three categories of devices

Input – the camera & scanner mainly

Display  – the monitor and projector

Output – printers

plus editing tools (Photoshop for example)

2. Device color spaces describe the range of colors (the gamut)

That a device can see, display or print

That space is specific to each particular device

All cameras don’t see the same colors

All monitors can’t display the same colors, etc.

Device color spaces are device-dependent

3. Editing color spaces such as Adobe RGB or sRGB (& others)

Specify a color range you can work in

While editing your image colors in a consistent manner

Largely independent of the edit program used

Guaranteed are the following –

1. Spaces are gray balanced

Colors where R=G=B will appear neutral

2. Spaces are perceptually uniform

Changes to lightness, hue, or saturation

Are applied equally to all the colors in the image

AND – Editing spaces are device-independent

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In tomorrow’s post, I’ll get more specific

In the meantime, here’s a preview

This illustration shows the gamut of

Two devices (monitor & printer),and

Two editing spaces (Adobe RGB & sRGB)

Note – monitors don’t all have the same working spaces

Further, sRGB is also a space for some monitors

In addition to being an editing space

Wide gamut monitors are common although new

sRGB covers roughly 1/3 & Adobe RGB 1/2 of all visible colors

sRGB is green & cyan “starved”

Printer color spaces depend on paper|ink combinations

You use a different space for every combination

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Note that some spaces may overlap others

 In this example, notably the printer space

Further, imagine that you have a wide gamut monitor, and

Are using Photoshop with a sRGB editing space, and

Want to print to the example inkjet

Say red specifically

Since each space shown has a different coverage of red, how is this done?

The answer is suggested in this workflow from yesterday’s post

For the next “thrilling episode”, tune in tomorrow

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2 thoughts on “Color Spaces – Color for Man & Machine

  1. Yes, thrilling! I’m learning something here — wasn’t that aware of the different gamuts of the different color spaces. Keep thrilling me 🙂

    • Thanks for the encouraging reply. The best (IMO) is yet to come. I’m enjoying what I’m learning more than you. Color is fascinating. 😉

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