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Color calibration 1


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									Color Calibration, Part 1: Learning the language
by Lesa Snider
The Graphic Reporter

We really don’t ask for much. We want/need our prints to match what we see on our screens. What’s the big deal? How can this be so hard? After a
few frustrating attempts at adjusting things on your own, you may start to research this phenomenon. Whoa! You suddenly find yourself assaulted with
all kinds of cryptic terms and acronyms that could send you running to the nearest pub, or worse, spending thousands of dollars on a color calibration
solution that you know nothing about. You could go out and buy a book but holy mother of THOR you don’t exactly have time to sit down and read a
big, honkin’ tome. There’s just got to be an easier way. In this article series, I hope to shed a bit-o-light on the mystery of color calibration. In part 1,
we’ll cover the most common terms associated with this evil mess, enabling you to speak its language. But first, let’s chat for a moment about why it’s
all necessary.

Why should I care?
We all know that computers are basically stupid until programmed. They need instructions for everything, including how to interpret and display color.
With so many different manufacturers of monitors, scanners, printers, cameras, etc., you can imagine it’s unlikely that they’re all getting the exact same
instruction set. Therein lies the problem. When the exact same color values are sent to two different monitors, the results usually vary. Same thing
happens when you send the exact same color values to different printers; they yield different results. The solution lies in a process somewhat analogous
(albeit more involved) to the way you can tell your camera what color is white (also called setting the white balance). With a little knowledge, we can
learn how to communicate with our devices regarding color, and improve their communication between each other, and avoid the dreaded print shock
syndrome when your print looks nothing like what you see onscreen.

What is color calibration?
This is the process of updating or recreating a device’s (scanner, printer, or monitor) color profile (defined below). All this means is that you’re
attempting to set the hardware and software so that optimum (predictable!) color results can be achieved. Once a device is calibrated, it can be
integrated into a color management system, which we’ll talk about later on in the series.

What is color workspace?
This refers to the working colorspace in which a current job is kept. Think of it this way: you pull a file out of a filing cabinet and place it on your desk
in order to work on it, right? And when finished your put it back into the filing cabinet, off your desk. Each time you open an electronic document, your
computer grabs it from the hard drive and tosses it into RAM (random access memory) for perusal and editing. Once you save and close it, it disappears
from RAM and resides simply on your hard drive, with the changes you just made. See the logic of something traveling from one place to another while
active, and then back? Same thing with colorspace. When you open a document in an image manipulation application like Photoshop, it’s tossed into
your current color workspace for editing. But you need to see it, right? Now your screen or monitor tries to interpret the color values it’s receiving from
Photoshop in order to properly display and update it as you are editing (it’s rather vital to see what the heck you are working on and what changes you
are making). To do this, the color values of your workspace need to be converted to the color values of your screen. This is called a “conversion” and it’s
being done constantly as the image is being edited and updated. These conversions are performed with (brace yourself)... math (shiver).

What are color profiles?
Every device, as we learned above, reproduces color differently because of the instructions it was given at “birth.” When color producing devices start
communicating with each other, they carry with them their own method of color interpretation. Remember the colorspace conversions we spoke of in
the paragraph above? Those conversions all require a profile. Your computer’s operating system supplies the screen (monitor or display) profile, which
makes sense if you remember that it’s the computer itself who’s sending the screen instructions and signals. The working colorspace of the current job
is determined by whichever colorspace you’ve chosen in Photoshop, under Color Preferences.

Remember how Photoshop dutifully notifies you when opening a document that the colorspace is different and wants to know if you’d like to convert it?
This means that the colors in your source document are in a colorspace which differs from the working colorspace you’ve chosen in Photoshop.
Photoshop knows this because the source document has a colorspace profile associated with it which define its color values. Each time you create a
new document in Photoshop, the profile of your current workspace is attached to it. Perhaps a few lightbulbs are beginning to flicker, yes?

Not only can each device and document have their own profiles, there are even profiles for specific combinations of printer, ink, and paper. Profiles can
be created manually or purchased, and we’ll discuss pros and cons of both in the next installment.

Take a rest now, and I’ll see you soon in Part 2 :)

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