With our focus on helping readers to achieve high-quality digital prints, we've often looked at hardware devices and software solutions for monitor calibration. However, a Canadian company has recently released a set of cards which, with supporting software, provides digital photographers with an easy and affordable way to calibrate their entire imaging workflow from capture to output. The Perfect-Pixs system has been developed by Ontario-based teacher and print-maker, Christopher Wade and it's the simplest and cheapest digital workflow calibration tool we've seen.
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With our focus on helping readers to achieve high-quality digital prints, we've often looked at hardware devices and software solutions for monitor calibration. However, a Canadian company has recently released a set of cards which, with supporting software, provides digital photographers with an easy and affordable way to calibrate their entire imaging workflow from capture to output. The Perfect-Pixs system has been developed by Ontario-based teacher and print-maker, Christopher Wade and it's the simplest and cheapest digital workflow calibration tool we've seen.
The Perfect-Pixs package consists of three cards plus a CD containing support files and instructions. These cards are also sold separately via the company's e-Bay-based online store. (Note: Shipping and applicable taxes are extra.) Each card is 25.4cm wide - big enough to be easily usable yet small enough for portability - and all are printed on a 1mm thick specially coated, matte finished board using archival inks at high resolutions. Properly handled and cared for, they should remain usable for years.
The cards are supplied with full instructions, and buyers who register their purchase receive a bonus set of instructions on 'How to Visually Calibrate Your Monitor'. The CD also contains TIFF and JPEG files that replicate the Zone card and Patches card, plus additional files with continuous and 2% step graduations and coloured squares. These are used when comparing the colours you see on-screen with the colours on the printed cards and form the basis of the visual calibration system for computer monitors.
The Zone card carries a calibrated grey scale with 11 individual zones, ranging from 100% black to 100% white plus continuous black-to-white and white-to-black scales. One of its most useful applications is for establishing exposure levels for digital cameras. To accomplish this, the photographer takes a spot meter reading from the 50% grey patch and uses it to see whether the camera over- or under-exposes. This test shot will also reveal any inherent colour casts in the camera and show how it records the full range of tones.
You can also check the camera's dynamic range by taking a shot of the Zone or Patches card. If you can't see any difference in the two or three patches at either end of the Zone card, the camera's contrast will probably be excessive and its dynamic range will be clipped.
Exposure accuracy can also be checked with these test shots by examining a histogram of the shot. The graph will show you where the exposure is positioned and you can set exposure compensation to counteract under- or over-exposure or use the Levels adjustment when editing the image to restore a normal brightness range.
The Patches card contains calibrated colour patches in black, 50% grey and white, plus six solid coloured squares (red, green, blue, magenta, cyan and yellow) and a grid of each of these colours at 10% tonal increments. Like the Zone card, the Patches card plays several roles. It can be used to show up any compression of colour rendition as well as for checking how accurately your monitor reproduces the key imaging colours: red, green, blue, cyan, magenta and yellow, by comparing the image files on the CD with the printed versions. You can also assess how accurately your printer reproduces the colours you see on the screen.
The instruction manual explains how to make these assessments and outlines the differences you should expect when viewing screen and printed output, which have radically different dynamic ranges.
Monitor calibration can also be carried out with the Zone and Patches cards, in conjunction with Adobe Gamma (or a similar software program). The monitor's brightness and contrast controls are first adjusted using the Zone card and then the Patches card is used to calibrate individual settings for red, green and blue.
Both cards can also be used as colour and tonal range references when shooting digital photos. As in the days of film, users have two options: including the card in the scene itself or taking an initial test shot under the same lighting. The latter is preferable as it gives you larger reference areas to work with and eliminates the need to crop out the reference cards. By previewing the reference on your camera's monitor and zooming in on specific colour or brightness patches, you will soon learn how your camera's colour reproduction - and also its LCD monitor display - are biased.
The reference images can also be used when editing shots to ensure all tones in the image are reproduced accurately. Using the levels adjustment plus the eyedropper tool, you can set the white, grey and black points from the reference to match those in the final image you will print.
The Custom White Balance card is pure white and is used for making manual white balance measurements. With an area of 516 cm2, it provides a large enough reference area for custom white balance measurement with any digital camera and also ensures consistency from one measurement to the next. We've found this card is easier to use and gives a far more accurate assessment of white balance performance with a wide range of digital cameras than a sheet of plain white paper.
The company has recently added several new cards to its line-up:
- a Colour Checker Target Card ($US5.95) containing reference patches of red, green, blue, cyan, magenta, yellow, black and white;
- a Colour Checker Grey Zone Reference Card ($US19.95), which has 30 patches covering the standard RGBCMYK and white patches plus difficult-to-reproduce colours like skin tones, aqua, olive green, ochre, maroon plus four shades of grey;
- a three-tone Mini Grey card ($US4.25) with white, black and 'grey-for-digital' patches;
- a Digital Target Grey Card ($US7.95), which has reference zones of black, white and digital grey plus four cross-hair targets to aid focusing - and capture accuracy.
- a Focus Chart and Grid Target (US $8.95) that can be used for checking autofocus functioning and accuracy and providing a focus point with difficult-to-focus subjects.
The PerfectPixs card set can be purchased online from www.pixelplace.ca for $49.95 Canadian (approximately $A57.50 plus $A6.90 postage). [27]