Calibrating, Printing and Proofing by the G7™ Method

Calibrating, Printing and Proofing by the G7 Method Version 6, August 2006
12 Soft Proofing (Video Proofing)
12.1 Basic requirements
Today's ICC color management allows a good CRT or LCD monitor (or even a high-quality video
projector) to display a very close simulation of a printed press sheet, under proper ambient lighting. But
achieving an optimum soft proof is not as easy as it might seem. Minimum requirements include;
• A wide-gamut, high-contrast monitor in good condition
• An accurate ICC profile of the monitor
• A good ICC profile created from the device or characterization data to be imitated
• Software capable of converting a CMYK image from the source profile (press) to the display
profile in absolute colorimetric mode – for example Adobe Photoshop
• A controlled viewing environment in which the monitor is the brightest element in the observer's
field of view, and in which the ambient lighting in which the press sheet or proof is compared to
the screen is the same 'color' and brightness as the monitor white point – for example a dimmable
D50 viewing booth like GTI's SOFV-1e.
12.2 Soft proofing in Adobe Photoshop
With some effort, a good soft proof can be displayed in Adobe Photoshop 7 or later using the
equipment, profiles, and conditions listed above, but Photoshop does not display CMYK files accurately
by default. Simply assigning the right profile to a CMYK image in Photoshop produces a 'pleasing'
image in which white and black contrast, paper color and maximum ink density may be inaccurately
displayed.
The following suggestions will help you display CMYK files more accurately in Photoshop;
• For greatest soft proofing convenience use Photoshop CS, not CS2.
• Create a large white (0,0,0,0, CMYK) image and assign your target profile to it.
• In Photoshop CS select View - Proof Setup - Simulate Paper White.
• Make sure the monitor hardware is set to maximum brightness, except when matching one
monitor to another alongside it, in which case set the dimmer monitor to maximum brightness and
reduce the brighter one to match it.
• Adjust the dimmable viewing booth alongside the monitor so that a piece of white paper (same as
used to make the CMYK profile) in the booth matches the brightness of the blank white CMYK
image on screen.
• Create an ICC Version 4 monitor profile with software that allows precise manual white point
adjustments, for example MonacoOPTIX Pro or ColorEyes Display.
• Calibrate the monitor white point till the white CMYK image is the same color as the paper. This
is relatively easy in monitor profiling software that allows custom 'x' and y' white point
adjustments, but difficult or impossible in software that provides only traditional selections like
'D50, D65' or '5000K, 5500K, 6000K, 6500K'.
• If possible, use the 'Measure' option to measure the viewing booth light source with the same
sensor used to measure the monitor.
• After adjusting monitor white point, the viewing booth's intensity may have to be re-adjusted.
12.2.1 Optimizing black point
In theory, the most accurate Photoshop soft proof is achieved with 'Simulate Paper Color' (CS2) or
'Simulate Paper White' (CS) and/or 'Simulate Ink Black'. Without any of these options dark black areas
may be too dark on screen, but when these options are chosen dark black areas may be too light
instead. The problem is meant to be solved with Version 4 profiles but apparently not in all cases.
36 Copyright © International Digital Enterprise Alliance, Inc. [IDEAlliance] (2006). All Rights Reserved.