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The need for color management Color management
1
P
hotoshop 5.0 was justifiably praised as a ground-breaking upgrade when it was
released in the summer of 1998. The changes made to the color management
setup were less well received in some quarters. This was because the revised
system was perceived to be extremely complex and unnecessary. Some color profes-
sionals felt we already had reliable methods of matching color and you did not need
ICC profiles and the whole kaboodle of Photoshop ICC color management to achieve
this. The aim of this chapter is to start off by introducing the basic concepts of color
management the first part will help you to understand the principles of why color
management is necessary. And as you will discover, there are some important historical
reasons why certain Photoshop users feel they have no need to use ICC profiled
color management. We will be looking at the reasons for this and then go on to
consider the advantages of an ICC profiled workflow and lastly, how to optimize the
Photoshop color engine settings. This latter section will take you step by step through
the Photoshop Color Settings interface.
The need for color management
An advertising agency art buyer was once invited to address a meeting of photogra-
phers for a discussion about photography and the Internet. The chair, Mike Laye,
suggested we could ask him anything we wanted, except Would you like to see my
book? And if he had already seen your book, we couldnt ask him why he hadnt
called it back in again. And if he had called it in again we were not allowed to ask
why we didnt get the job. And finally, if we did get the job we were absolutely forbidden
to ask him why the color in the printed ad looked nothing like the original transparency!
Adobe Photoshop 7.0 for Photographers
by Martin Evening, ISBN
0 240 51690 7
is published by Focal Press, an imprint of Elsevier Science. The title will be available from the
beginning of August 2002. Here are four easy ways to order direct from the publishers:
By phone: Call our Customer Services department on 01865 888180 with your credit card details.
By mail: Write to Heinemann Customer Services Department, PO BOX 840, Halley Court, Jordan
Hill, Oxford OX2 8YW
By Fax: Fax an order on 01865 314091
By email: Send to bhuk.orders@repp.co.uk
By web: www.focalpress.com.
Orders from the US and Canada should be placed on 1-800-366-2665 (1-800-366-BOOK) or tel:
314-453-7010. Email: custserv.bh@elsevier.com The title will be stocked in most major bookstores
throughout the UK and US and via many resellers worldwide. It will also be available for purchase
through the online bookstores Amazon.com and Amazon.co.uk.
The following extract is part one of a guide to Photoshop 7.0 color management. Adobe Photoshop 7.0 for Photographers
<www.photoshopforphotographers.com>
2
That in a nutshell is a problem which has bugged us all our working lives. And it is
one which will be familiar to anyone who has ever experienced the difficulty of
matching colors on a computer system with the original or a printed output. Figure
4.1 has two versions of the same photograph. One shows how the Photoshop image
is previewed on the monitor and the other is an example of how a printer might
interpret and reproduce those same colors. Why can there be such a marked differ-
ence between what is seen on the screen and the actual printed result? The computer
monitor will have manual controls that allow you to adjust the brightness and con-
trast (and in some cases the RGB color as well), so we have some element of basic
control there. And the printer will also probably allow you to make color balance
adjustments, but is this really enough though? And if you are able to get the monitor
and your printer to match, will the colors you are seeing in the image appear the
same on another persons monitor?
Why not all RGB spaces are the same
Figure 4.1 The picture on the left shows how you would see the Photoshop image on your screen
and the one on the right represents how that same image will print if sent directly to a proofing
printer without applying any form of color management. This is an actual simulation of what happens
when raw RGB data is sent without any form of compensation being applied to balance the output to
what is seen on the screen.
You might think it is merely a matter of making the output color less blue in order to successfully
match the original. Yes, that would get the colors closer, but when trying to match color between
different digital devices, the story is actually a lot more complex than that. The color management
system that was first introduced in Photoshop 5.0 will enable you to make use of ICC profiles and
match these colors from the scanner to the screen and to the print proofer with extreme accuracy.
Client: Clipso. Model: Sheri at Nevs. Color management
3
What you have just witnessed illustrates why color management is so important. It is
all very well getting everything balanced to look OK on your monitor and knowing
how to tweak your printer settings to look right. But there is a better way, one that
will allow you to mix and match any number of digital devices. Go into any TV show
room and you will probably see rows of televisions all tuned to the same broadcast
source but each displaying the picture quite differently. This is a known problem that
affects all digital imaging devices, be they digital cameras, scanners, monitors or
printers. Each digital imaging device has its own unique characteristics. And unless
you are able to quantify what those individual device characteristics are, you wont
be able to communicate effectively with other device components and programs in
your own computer setup, let alone anyone working outside your system color loop.
The way things were
What follows is a brief summary of working practices in the repro industry, but keen
amateurs might also be interested to learn about some of the background history to
color management. Ten years ago, most photographers only used their computers to
do basic administration work and there were absolutely no digital imaging devices to
be found in a photographers studio (unless you counted the photocopier). At the end
of a job we would supply transparencies or prints to the client and that was the limit
of our responsibilities. Our photographs then went to the printer to be digitized using
Figure 4.2 All digital devices have individual output characteristics, even if they look identical on the
outside. In a TV showroom you will typically notice each television displaying a different colored image. Adobe Photoshop 7.0 for Photographers
<www.photoshopforphotographers.com>
4
a high-end drum scanner to produce a CMYK file. The scanner would be configured
to produce a CMYK file ready to insert in a specific publication. If color corrections
were required, the scanner operators carried this out themselves on the output file.
These days a significant number of photographers, illustrators and artists are now
originating their own files from digital cameras, desktop scanners or directly within
Photoshop. This effectively removes the repro expert who previously did all the
scanning and matching of the colors on the press. Imagine for a moment what would
happen if our traffic laws permitted a sudden influx of inexperienced and unaccom-
panied teenage learner drivers on to our roads? This will give you some indication of
the printer rage that ensued when Photoshop users began delivering digital files
instead of transparencies. There is no getting away from the fact that if you supply
digital images to a printer, you will be deemed responsible should any problems
occur in the printing. This may seem like a daunting task, but with Photoshop it is
not hard to color manage your images with confidence. It need only take a few min-
utes to calibrate your monitor with the Adobe Gamma control panel and to configure
the Photoshop Color Settings. But well come to that later on.
CMYK color management
Printers naturally have an output-centric view of color management. Their main
concern is getting the CMYK color to look right on a CMYK press. Accordingly,
you will hear an argument that suggests you dont need ICC profiles to get accurate
CMYK color. In fact, if you know your numbers, you dont even need a color moni-
tor. In this respect you can say they are right. These proven techniques have served
the printing industry well for many years. But most Photoshop users and especially
those who are photographers, face a far more complex color management problem,
because we dont all have the luxury of managing the one scanner linked to a single
press. We quite often have to handle digital files sourced from many different types of
RGB devices such as: digital cameras, desktop scanners, Photo CD, picture libraries etc.
RGB devices
If your production workflow is limited to working with the one high-end scanner
and a known press output, then the number of variables in your workflow is limited
and it would not be difficult to synchronize everything in-house. But this is not the
experience of an average Photoshop user. Instead of handling color between a few
known digital devices in a fixed loop, you are faced with files coming from any
number of unk