Professional Photography : color management

Color Management in Windows Vista vs. Mac OS X

Eileen Fritsch — Mon, 23 Nov 2009 14:01:00 GMT

I am a cross-platform kind of guy. I have my wonderful black MacBook as well a Dell desktop running Windows Vista Professional. When I teach a class on color-management or other aspects of photography, I always like to know which platform each photographer is using.

In most cases, the photographer’s operating system of choice has to do with experiential history—whichever platform the photographer first started using is what they have continued to use. Sometimes I hear about photographers who have switched from OS X to Windows and vice versa.

One reason I use both operating systems is because I frequently get questions about how Windows integrates color-management differently than Mac OS X. Different versions of Windows handle color management differently, So let’s focus first on Windows Vista.

Storing Profiles in Windows Vista: In Vista, the ICC profiles for your displays, scanners, cameras, and printer/media combinations are stored in the Windows/System32/Spool/Drivers/Color directory. If you haven’t done so yet, you might want to make a shortcut on your desktop to the contents of the directory.

One of my favorite color-management features of Windows is that if you acquire a profile from an outside source (either by downloading one from a website or having one sent to you via e-mail), you can easily copy the profile into the proper directory.

Simply right-click on the profile and select Install Profile. This simple process will copy the profile into the Windows/System32/Spool/Drivers/Color directory where it will be available for ICC-aware applications such as Photoshop and Lightroom. Mac OS X does not have this feature. If you are wondering where profiles reside in OS X they are located in you Library/ColorSync/Profiles directory for either the root or user level.

Display Calibration: When you calibrate and profile your display for color-accurate editing, you should know that one of the trickier things about Windows is that the video card driver must support a software rewrite of the default gamma tables in the video card LUT (Look Up Table).

X-Rite has a tool to test this. Click here to check it out.

If your video card does not support modifiable video LUT's then you may have to upgrade or downgrade your video card driver, or even possibly purchase a new video card. This is common on many older laptop PCs.

Mac OS X works on a totally different premise and ColorSync can use a table in the display profile to load the calibration data to the video card.

Windows Color Systems: One of the biggest changes in Microsoft color management was the introduction of WCS or Windows Color System for Vista. This was introduced during the development of Vista. This initiative was a collaboration with Canon, and uses Kyuanos technology developed by Canon. WCS is very powerful and has a host of totally new features designed to evolve color in the OS.

We’ll talk about some of these improvements in more detail in a separate post, but some of the benefits of the Windows Color System include a completely revamped color infrastructure and translation engine called CITE, an enhanced color-processing pipeline that supports greater bit depths and multiple color channels, and support for scRGB (a wide gamut RGB space developed by Microsoft and HP). Most notably, Windows Color System provides an improved user experience through a centralized color control panel.

Where Vista Still Lags Behind Mac OS X: The biggest issue with color management in Windows Vista is the lack of integration of the display profile into every application.

One of the beauties of Mac OS X is that every application uses the display profile to render color. This means that if an image has an embedded profile, OS X will convert the color data and give you the correct appearance on your screen. Your images will look the same whether you are viewing them in Photoshop, Preview, Safari, and Mail.

This is not true for Windows Vista. In Vista, applications need to be ICC aware to accurately display color images that have been created and saved in color spaces other than sRGB.

This means that images that you have edited and stored in the Adobe RGB or ProPhoto color spaces will look different in Internet Explorer, Outlook, or Microsoft Picture Viewer than when you edited them in Photoshop or Lightroom.

For more information on photography and color at Microsoft visit www.microsoft.com/prophoto and www.microsoft.com/whdc/device/display/color/WCS.mspx

Marc Aguilera is a part-time professional photographer and Photography and Digital Workflow instructor for University of California San Diego Extension. He is also an Apple Certified Professional in Color Management and Apple Certified Pro Trainer. He is a color expert for X-Rite's Color Services division and speaks on behalf of the creative community at AIGA's HOW Conference and at the PIA/GATF Color Conference each year. He has a BA degree in Visual Arts from Univeristy of California-San Diego. You can reach him through his blog at http://www.colorcritical.com.

Choosing the Right Color Space

Eileen Fritsch — Sun, 01 Mar 2009 20:03:00 GMT

By Jon Canfield

One area of contention among digital enthusiasts is the choice of color space for doing editing work. Almost every camera gives you the option of sRGB or Adobe RGB at capture. sRGB is a good choice for JPEG capture, especially if you intend to place your images online. It’s a standard that is safe for most situations and displays. But is it appropriate for printing? That depends a bit on your printer and your workflow.Most of the better inkjet photo printers support a color space closer in size to Adobe RGB. Some of the newest printers are capable of printing colors outside of Adobe RGB as well, which makes ProPhoto a consideration.

How much difference is there? Figure 1 below shows both sRGB and Adobe RGB spaces, along with the ProPhoto color space. In this figure, the red area is the sRGB color space, green indicates Adobe RGB, and the outside line is ProPhoto.

Figure 1

It’s pretty easy to see that ProPhoto covers just about every imaginable color, so why shouldn’t you just select this color space and be done with it? The main reason you might not choose ProPhoto is that you can have colors in your image that will be significantly out of gamut for your output device.

Let’s take a look at Figure 2 below. This shows the ProPhoto color space as the large area with the new HP Baryte Satin Art Paper on an HP Designjet Z3200 printer as the inside area. The Baryte paper is an excellent media with a large color gamut, but it’s significantly smaller than ProPhoto. So, if you print to this paper you run the risk of having colors that are out of gamut and will need to be mapped to a new color.

Figure 2

But, if we work in Adobe RGB, you can see in Figure 3 below that Baryte actually has colors that can be reproduced outside of this range. You would end up having colors clipped and remapped that weren’t out of range of your printer in the yellow and cyan spectrum.

Figure 3

If you’re working in Photoshop Lightroom, this is a moot point because Lightroom uses ProPhoto as its working color space. Photoshop however gives you the option of selecting a working space.

My recommendation to attendees at my workshops is to use the ProPhoto space if they’re doing their own printing. I’d rather have color in my image that is beyond the paper limits than have colors lost that I could have reproduced.

But, does it matter? After all, as I mentioned at the start of this post, your camera most likely only has sRGB and Adobe RGB as choices. If you’re shooting RAW though, a color space isn’t actually applied until you convert to an image format such as TIFF or PSD. If your image is already in one of these formats, going from Adobe RGB or sRGB to ProPhoto isn’t going to improve your output. It would be like moving a gallon of water from a one-gallon bottle to a five-gallon bottle. You still have a gallon of water.

If you’re not shooting RAW, you’re already giving up quite a bit of image data, so I’d suggest using Adobe RGB to keep as much color information as possible unless you don’t print, or you send your work to an online photo service such as Mpix or Snapfish to be printed. In that case, sRGB will save you a bit of time and give you results that will be as good as you can get from the source files.

Creating a Digital Darkroom for A Color-Managed Workflow

Eileen Fritsch — Tue, 09 Dec 2008 00:22:00 GMT

By Marc Aguilera

Creating a digital darkroom is one of the final tasks in implementing a precision color-managed workflow. It’s one of the often overlooked aspects of most digital photographic setups, however when taken seriously, a properly controlled “darkroom” and use of ICC profiles for your devices will yield the closest possible screen-to- print match.

First let’s talk about viewing conditions in the digital darkroom. Note that if you really want to go deep into this subject then I recommend you purchase the ISO Standard 3664:2000 entitled Viewing Conditions – Graphic Technology and Photography. If you would simply prefer the ‘just-tell-me-what-I-need-to-know’ version, then continue reading.

ISO 3664 basically states the obvious: (1) Light affects color; and (2) Your individual experience of color ultimately is subjective. It also states that while color measurement plays an important role in color control, color measurement will never replace the human observer for final assessment of quality. Furthermore, without question the best viewing condition is one which the final print will be seen, Nevertheless, ISO 3664 aims to provide a standardized specification for illumination and viewing conditions that when properly implemented ”...will reduce errors and misunderstandings caused by such deficiencies and inconsistencies.”

In other words, adhering to certain standards for viewing conditions within a digital darkroom makes it possible to achieve the best possible environment for making critical comparisons between transparencies, reflective photographic or photochemical prints, as well as overall appraisal of images on color displays which are not viewed in comparison to a hard copy.

Viewing apparatus.
When creating your digital darkroom, pick a light source that has the spectral power distribution of D50 - Daylight – 5000 Kelvin. You can get these types of lights from a variety of sources, including Solux, Just Normlicht, GTI, and X-Rite. The light source is crucial if you want images on your display and prints to come close to matching. The most economical way to go is to go with a Solux Task Lamp, although I prefer a well designed light booth. If you decide to build your own light booth be sure to minimize specular reflectivity and be sure the color of the booth is neutral. The color rendering index of the light source shall be 90 or higher and the illumination shall be 2000 lux +/- 500. The most important things to remember are that: (1) Light can greatly affect how your experience color; and (2) The best light source for viewing is D50 with minimal reflectivity, neutral colors for the apparatus, and 2000 lux of light.

Shown here is the digital darkroom of Harvest Productions in Yorba Linda, CA, an encompus color services account for which I provide training and consultation in the integration of ISO 3664:2000. It is a non-manipulated image of a typical workday. The original paintings and inkjet-printed reproductions are compared under a D50-balanced fluorescent light from GTI. However, the light source is reflected at an angle to reduce specular reflectivity. This was a custom design by Harvest.

This image is on location at the Color Control Freak Seminar sponsored by X-Rite and PANTONE. To demonstrate ISO 3664 principles, I brought along my Just Normlicht mini 5000 light.

Surroundings
ISO 3664 states that the area immediately surrounding the displayed image shall be neutral, preferably dark gray. Also, the display should be situated so there are no strongly colored areas (including clothing) directly in the field of view because these may cause reflections in the display screen. Ideally all walls, floors, and furniture in the field of view should be grey and free of any posters, notices, pictures, wording or any other object which may affect the vision of the viewer.

As far as any interior paint is concerned ISO 3664 does not mention a particular paint or even Lab* value as long as it is neutral gray. My personal preference is the equivalent to Munsell N5 Gray, which in a PANTONE interior paint translates to 17-4402 TPX Neutral Gray and sells for $135 with Key Primer. If you’d rather go for a less expensive but equally good paint try Dunn Edwards Galax-z DE 1087 Dash of Ebony for around $45 per gallon.

I should also stress that the level of ambient light (the light in the environment surrounding your display) should be quite low. In fact, ISO 3664 states that ambient light should be under 64 lux and preferably under 32 lux of light. You can use an instrument such as X-Rite’s i1 Display and i1 Pro with free software called i1 Share to measure the amount of ambient light and its color temperature.The more ambient light there is in the room the more your display will have to compete with it, making the the likelihood of screen-to-print match that much more difficult. Do what is necessary to lock out the ambient light, even if this means shielding windows or turning off the surrounding lights.

Display Calibration and Profiling
It goes without saying that when creating a color-managed digital darkroom the display must be calibrated and profiled. The question really becomes what set of criteria do we calibrate to?

Essentially when you calibrate, you should choose a particular white point. ISO 3664 uses D65 as a white point and luminance must be over 75 cd/m2 (candela’s per meter squared) and should be over 100 cd/m2. I prefer 110-130 cd/m2. Also gamma should be set to 2.2. You may prefer a white point of D50 and gamma 1.8 if you send most of your work to publication but this is a choice you must make.

I learned years ago from one of my teachers in color that your viewing white point must match your display white point in order for the colors to really match. This advice has been important. Sometimes a display white point needs a bit of tweaking in order to get the best screen-to-print match. At encompus, we all have our displays calibrated to D65, 120 cd/m2, gamma 2.2. I get a decent screen to print match with my Just Normlicht mini 5000 light box.

Final Considerations
The major advantage of creating a digital darkroom is that you will gain efficiency in precision editing, especially when viewing color on screen compared to color on your print. Your viewing environment greatly affects how the eyes perceives color. A neutral environment with the correct lighting and positioning combined with a calibrated and profiled display and ICC workflow are the key elements in creating a color-managed digital darkroom.

Fine-Art Reproduction Part 2: What You Need to Get Started

Eileen Fritsch — Thu, 24 Jul 2008 20:26:00 GMT

By David Saffir

Professional photographers are uniquely qualified to get into the fine-art-reproduction business because the element most critical to success is a quality image capture. Photographers not only have a discerning eye for color and detail, but also tend to have the best capture equipment. For fine-art reproduction, the lens, digital sensor, and software used to process the RAW digital image files have to be pro level, with no compromises.

Specialized Training
Before you invest in any additional equipment, it might be wise to invest first in some training—so you can see for yourself how the fine-art reproduction workflow differs from printing your own photographs. During a good training session, you’ll see why it’s not smart to try to cut corners when it comes to buying quality equipment.

For example, the training should cover specific capture, color control, and printing techniques that have proven to be successful in faithfully reproducing the colors used in the original artwork. This usually requires one to two full days of work, with lessons focused on image capture setup, color management, media selection, image editing and print prep. You also need to understand how the build good relationships with artists and some of the printmaking traditions specific to the art market. Once you’ve been trained, you’ll better understand the rationale behind all the other elements listed below.

The Right Lighting Setup
Digital image capture for fine-art reproduction is based on good old-fashioned copy work. It requires two to four color-corrected lights (strobes or continuous), diffusers or softboxes, a sturdy tripod or studio stand, and a stable copy stand that can support artwork in a range of sizes. You could use continuous lighting using tungsten bulbs, but I don’t recommend it. Even though we can correct color pretty well, a light source that isn’t color-balanced can lead to a number of problems, including excessive time in post-production trying to correct color distortion. It’s better to use color-corrected halogen or fluorescent lights.

A Good Camera and Lens
I use a Hasselblad H-series camera and a Phase One digital back. I really don’t see any reason to use film for fine-art reproduction unless your client wants to archive an image on film for some reason. With my equipment, I have gotten excellent results with images up to 40 x 60 in. in one frame, and panoramas up to 10 ft. long. It is quite feasible to shoot even larger pieces in one frame. Or, you could shoot the image in quarters and stitch them together in Photoshop. The recently released Phase One/Mamiya medium format combination is interesting, and costs less than competing products. A new Mamiya kit with an 80 mm lens has been reported selling for $10,000. You could use a high-end DSLR, like the Canon Mark II and III-series, or the Nikon D3 series on many pieces of artwork, but successfully reproducing a large painting usually requires the resolution that only a medium-format digital camera can provide. In any case, the cost of acquiring technology is lower and dropping every month. Used equipment is frequently an option as photographers trade in and trade up.

Procedures and Tools for Controlling Color
Reproducing artwork requires processes for controlling color at every step in the process, from capture to output. The more careful you are in controlling color, the less time and materials you’ll waste trying to get your print to match the original. If you’re serious about your digital photography, you probably have already invested in a high-quality monitor and tools for keeping it calibrated so you can accurately preview and edit your images on screen.

The most straightforward way to control color while shooting is to:

Ensure that the target artwork is evenly illuminated from corner to corner and from side to side, within 1/10 of an f-stop;
Shoot at lowest ISO available;
Use RAW capture; and
Include a grey card or white/grey/black target in your shot. (This will be an enormous help when processing the image on your computer.)

Finally, you will want to be able to routinely create accurate custom color profiles for each type of print media you use.

You can use a handheld spectrophotometer (such as the ones made by X-Rite), or an online service (which can be pricey). Or, you can buy a wide-format inkjet printer that has the custom-profiling functionality built-in (such as the HP Designjet Z3100). Being able to obtain accurate color profiles is essential, but that’s only part of the game. In order to efficiently be able to produce a print that looks just like the print you output six months ago, your profiles must be re-created or updated periodically.

A Pro-Model, Pigment-Ink Printer
You’ll need access to a wide-format, wide-gamut printer that can handle a variety of media types, media thicknesses, and roll widths. Most people in the fine-art reproduction business have a printer that can print up to 44 in. wide. Many printmakers use devices that can print up to 60 and 64-in. wide. These wider printers can be used not only to make larger prints, but also to efficiently print higher volumes of smaller prints.

If you don’t yet own a wide-format printer, some studios will rent you access to their printers for a day or half-day. In other areas of the country, you may want to purchase one for yourself. To produce the wide color gamut needed to accurately reproduce fine art, your printer should have at least eight ink channels. In my opinion, having 12 ink channels is better because the color palette and the control provided over color and density is noticeably superior.

It’s also important to be sure that the printer uses pigment inks, instead of dye inks. When used with reputable brands of art papers and canvases, pigment inks can create prints that will last well over 100 years without noticeable fading if they are properly protected and displayed. After you’ve equipped yourself to go into the fine-art reproduction business, the next task is to attract customers. I’ll share a few tips on marketing in my next post.

Orange Roses and Green Skin

BlogArchive — Wed, 25 Apr 2007 13:53:00 GMT

By Jon Canfield

I’m always surprised when a pro photographer gives me a blank look when I ask about their color management practices. This usually comes up when they’ve sent an image or group of images to me to print for an exhibition or limited edition and the colors are obviously off in tone.

The conversation often goes something like this:

Me: “The color balance on these images is off. When was the last time you calibrated your display?”

Client: “What’s that?”

Me: “Have you ever run a utility to make your monitor more accurate?”

Client: “No, I just adjust the monitor until it matches the print”

And there is the problem – they’ve done a calibration of sorts, but it’s exactly the wrong kind. The only time colors will ever match is on their printer and monitor combination. When viewing other images, or when sending images out, it’s a crap shoot on what things will look like.

Color management used to be considered black magic by many of us. The software methods were unreliable and the hardware was expensive and hard to use. That’s all changed, and for the better (except for the software method which is still unreliable).

With hardware devices starting at $60 or so, there is no reason your monitor shouldn’t be displaying accurate color. Yes, you can spend more for an advanced calibration that provides more control over the process. But unless you plan to create printer profiles, you’ll only be investing less than $250.

If you’re a working pro, that investment is quickly repaid in reduced editing and correcting time at the computer. If you’re an amateur, you’re still going to reap the benefits of color correctness, and save time and money when you print.

As a sign of just how mainstream color management is becoming, the HP Designjet Z2100 and Z3100 printers now include built-in color calibration and profiling hardware to ensure accurate color reproduction. The time and cost savings of this feature is tremendous, and the improved accuracy of prints is obvious. For even more control, and adding the ability to calibrate your monitor, the HP Advanced Profiling Solution also includes hardware to calibrate your display.

Regardless of your skill level, if you enjoy printing, editing or even just viewing images, a calibrated display should be considered mandatory. Why not try it and see?

The Importance of Being Calibrated

Eileen Fritsch — Tue, 31 Oct 2006 20:45:00 GMT

[MarcAguileraBio]

I am essentially lazy. I want to take great pictures at the start, then immediately go to print or the web with very little post production. That’s why I’m a digital purist and use color management to simplify my digital experience.

When I shot film, I looked for great light and always made sure I captured exposure that would produce a good negative or transparency. I was hard on myself if I had to rely on post processing to fix my mistakes. Even in the darkroom I liked to use the same few contrast filters for black and white printing. I was a film purist then and am a digital purist now.

As such, I have a mantra that really helps in dealing with digital imaging and printing: “Be Calibrated.”

Calibration is simply: To change the state of a device to conform to a known specification. It’s similar to a car tune up in which a mechanic checks how an engine is currently running, then makes the necessary changes to make the engine operate as it was designed to.

In the digital photographic workflow, I calibrate at every step. I calibrate my monitors with the Gretag Macbeth i1 to conform to a known luminance, gamma, and color temperature. When I shoot with my Nikon D200, I make sure I have calibrated to a known white point. I do this by setting a custom white point with a Gretag Macbeth White Balance Card.

Most importantly, when I print to my HP Designjet 130 and 90 I make sure that I use the “Automatic Closed Loop Color Calibration” feature on the printers. To see if there has been a drift in performance (which is a signal to re-calibrate), I send a copy of the test file shown here and compare it with a previous version. If the appearance of the colors has changed, I re-calibrate.

In every city in which I teach the Color without Limits seminar, one of the questions I hear most often is, “How often do I need to calibrate?” My answer is simple: “I re-calibrate only if I see a drift.”

A certain amount of drift occurs in all printers (and other digital color devices), no matter who makes them. Densities (and sometimes even hues) can change over time or when a new ink cartridge or printhead is installed.

It’s important to check for drift every time you set out to do a print run. Whenever I print, the first thing I do is print my test file. If it looks good, I am good to go. If it looks different than my last test print, I restart the calibration process.

Consistency is essential to managing color. Being calibrated means I can rest assured I will remain consistent.

The importance of being calibrated is that if I am calibrated, I have a better chance that my profile will produce satisfactory results.

Like I said, I am lazy. Really I am. I want to take great pictures and then make great prints with as little time in my digital darkroom as possible. So go on, be calibrated and I bet it will change your workflow forever.