COLOUR MANAGEMENT profiling practicalities 22 <strong>Imaging</strong> <strong>12</strong> autumn 2002
Getting to grips with colour management THE THEORY’S FINE, BUT HOW DO YOU ACTUALLY DO COLOUR MANAGEMENT? WHERE DO YOU GET THE ICC PROFILES FROM AND WHAT SHOULD YOU DO IF THEY’RE MISSING? MICHAEL WALKER TAKES ADVICE. W e all want to get colour right. And we want it to be right everywhere. When it was one scan for one print job that wasn’t too hard to achieve, but now it’s one scan (or supplied image) for everything – print use and re-use on a variety of stocks in different publications, plus possible Web and other screen-based uses. Colour management is the only way to get consistent colour, but what do you actually need to do to implement it? The key to colour management based on ICC (International Colour Consortium) profiles is to have a profile for every device in the repro chain that can reproduce colour. The profile describes the colour behaviour of each device in such a way that its peculiarities can be accounted for when making design and production decisions. So that’s a profile each for the scanner (or digital camera), the monitor on which you view and edit images, the digital proofer and the eventual output device – typically but not necessarily an offset press. As we’ll see, in the real world, it might not be possible or absolutely necessary to have all of these, but let’s first look at how you acquire them. Repro quality flatbed scanners ship with default profiles which are usually specific to the model rather than the particular unit. Although this is a reasonable start, it’s better to profile your own scanner. To do this you scan a supplied transmission or reflection target and use profile-creating software such as <strong>Fujifilm</strong>’s ColourKit Profile Maker (available separately, though input profile creation capability for <strong>Fujifilm</strong> Lanovia Quattro scanners is included with the bundled version of ColourKit). This compares the measured colour values from the scan against the known values of the target and creates an input profile that you can then use with reflective or transparent originals respectively. A further refinement is to make profiles for different original types, particularly brands of transparency film, as each has its own colour characteristics. Screen test So much for profiling captured images. What about viewing them? Most good monitors ship with a supplied profile but CRT monitors are prone to drifting with age (and even during the day), so if you’re serious about getting accurate on-screen colour you’ll need to make your own monitor profile. Profiling monitors is a little more tricky and involves additional hardware, in the form of a colorimeter or spectrophotometer that attaches to or is suspended in front of the monitor. This measures the colour values as a series of test colours are displayed. Again, the displayed colours are compared to the reference colour values and a profile generated by the profile making software. The newer flatscreen LCD monitors such as Apple’s Studio Display range appear to be much more stable in their colour behaviour, but note that colour measuring devices for monitor calibration that attach by suction can distort these displays and produce invalid results. As well as making sure you choose profiling software that’s compatible with your system (most are designed to work with Macs; you might have more difficulty if you’re Windows-based), think about whether the associated hardware is going to cause problems like this. Who’s going to do it? At this point it’s worth pointing out that you don’t have to profile all your screens, only those on which colour adjustments are made, so don’t bother with systems that are used only for page layout. Also, you don’t necessarily have to buy all the colour measurement gear and do it your- COLOUR MANAGEMENT WITH FUJIFILM If you buy a <strong>Fujifilm</strong> scanner or digital proofer, this is what’s included. Finescan 2750 and 2750XL Both scanners ship with <strong>Fujifilm</strong> ColourKit for image editing, re-processing and SOOM (scan once output many, see p28) functions. Includes wide range of negative and transparency profiles for different film types plus many output profiles. Can import third-party ICC profiles and images. Lanovia Quattro Ships with ColourKit as above, but also includes a cut-down version of ProfileMaker to enable users to make custom input profiles for their own scanner. Pictro Proof <strong>Fujifilm</strong>’s high quality proofing system is driven by the GMG RIP. This uses a unique 4-dimensional profile system and includes the tools to create and edit the profiles. Ready-made profiles are available to accurately simulate a wide variety of printing and proofing processes. <strong>Imaging</strong> <strong>12</strong> autumn 2002 23
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