Title: February 2005: Color Management in a Nutshell Post by: admin on May 27, 2009, 03:34:51 AM Color Management in a Nutshell
Background In my Over the Gamut and Through the Woods column from August 2004, I made an attempt to explain how to use color management and ICC profiles. In this article, we take a step back in order to discover whether or not we really need color management and we'll discuss some alternatives. As you can see by the August 2004 article, moving into a color managed workflow requires the use of ICC profiles which you may not be familiar with initially. In addition, acquiring these profiles is not always free and may require at least some minor investment. Ultimately, your investment of some time and money can pay off in the form of more accurate color on screen and in print, but is it worth it?
The naked eye Assessing color by eye is a simple
process that involves some very complex issues. We may
look at a printed photo and discover that it looks very
dull with washed out colors. This is a simple assessment
but it can be caused by a multitude of problems. Simply
cranking up the saturation on the image and reprinting
may solve the problem to your satisfaction, or it may
create other problems like loss of detail in bright
colors like blue sky. You might even look at a printed
photo in your office under fluorescent lights and notice
that a blue flower looks too purple, only to take the
same print to a window and the flower appears the proper
shade of blue under outdoor lighting. Assessing our needs Rather than try to understand all these interactions, why they happen, and the possible fixes, let's ask ourselves some simple questions to help us determine whether or not we really need to step into the world of color management and ICC profiles.
The color management investment Time and money are the major costs of a color management workflow. It will take a little reading to understand how to use ICC profiles in a color managed workflow and may actually complicate your workflow a bit if, for example, you change from one type of photo paper to another and now find that you need to acquire a new ICC profile for the new paper. In a non color managed workflow, you would just print on the new paper and experiment a bit. If you see something you don't like, you can change some print driver options or tweak the image and reprint. In a color managed workflow, use of the new paper is less of a manual effort and more of a scientific measurement process. While it may take some extra time up front to print test targets and create an ICC profile for the new paper, it does at least guarantee some level of color accuracy and in the long run may save a lot of time by eliminating reprints, manual tweaks, and fiddling with image edits. So let's say you'd like to give it a try, but what about the monetary investment? If you use your monitor as a "draft" view, are mainly concerned about color accuracy in prints, and don't do a lot of image editing with respect to color, you might be able to get by with just profiling your printer to create an ICC profile for the printer. A low cost printer profiling tool such as my own Profile Prism is a good investment for getting color accurate prints by allowing the profiling of any printer/ink/paper combination. Such a tool will cost about $79. But what if you don't have a scanner? A good flatbed scanner is required to be able to profile a printer because a scanner is used to "read" the printed target along with a reference target to make the adjustments in the profile. If you have an old scanner or your current scanning software is inadequate, the scanner may not be good enough to create accurate printer profiles. If that's the case, add about $100 to $120 for a good scanner like the Canon LiDE 80 that is capable of creating excellent printer profiles when combined with scanner based printer profiling software. Starting from scratch, we can now create our own printer profiles for any inket or dye sub printer, paper, and ink combination for a monetary investment of about $200. Considering the price of ink, photo paper, and time, that's not bad, but what about the monitor? If you do decide to do some edits and work on color in your images, your monitor may also need a profile because the edits you do on screen might not look the same when you print. Although your printer is printing accurate color via a printer ICC profile, your monitor may have some issues with accuracy. You can do a visual "calibration" of your monitor using a monitor calibration tool like Adobe Gamma or the monitor calibration tool that comes with Profile Prism, but realize that this is not as accurate as profiling. To create a truly accurate profile for your monitor and "close the loop" on color management, you will need to buy a colorimeter that attaches to your monitor. The colorimeter takes actual readings and creates an accurate profile. You can get a good monitor colorimeter with software for $250 to $300 at places like ColorVision or Monaco Systems. When we add these up, we're at $500
to take total control of color. The input device (camera)
needs a profile too, but it is beyond the scope of what
most people will be able to do to create camera profiles.
The better/professional cameras usually come with a
"color space" setting which is the same thing
as a profile. For example, set your camera to sRGB color
space, and all images from the camera will be in the sRGB
color space profile. Set it to Adobe RGB, and all images
will use the Adobe RGB profile. If not specified or
selectable in your camera, sRGB is the only real choice.
Just remember that a full color managed workflow requires
an accurate ICC profile for both the input device (camera/scanner)
and the output device (monitor/printer). If you are
missing an ICC profile on either side of the input/output
equation, accuracy may be questionable. Go or no? Ultimately your decision on whether or not to adopt a color managed workflow will depend on your wants and needs. If you are a professional or a semi-pro who occasionally sells prints or does work for publications, you will probably want to use color management because the benefits will show in your work and your time/money invested will come back to you. Color management via ICC profiles is currently the only method of dealing with color that can actually ensure some level of scientific accuracy in the results. If you are a "casual shooter" who prints a few photos from time to time and you don't consider digital photography a hobby, you may be hard pressed to justify the time and money investment required in a color managed workflow. This certainly doesn't mean you
need to be a pro to justify color management. You might
simply be someone who takes pride in their photography
and you want that to show in your photos. Different
combinations of equipment (cameras, scanners, monitors,
and printers) work better together and you might be using
a combo that produces very adequate results without
fooling with color management. On the other hand, you may
be someone who has been plagued with inaccuracy in
certain colors in your prints and you want a better way
to solve the problem than the endless moving of sliders
in your image editor. Some problems are very difficult to
solve by manual tweaking but are easily solved using
color management. Here is just one
example of how different equipment can
render different results and how color management can
bring them together in a scientific, measurable way with
no (or very little) manual tweaking. Mike Chaney |