Workflow

The chosen zone system application workflow begins with a digital camera and ends with an inkjet printer.

Cameras

• Nikon D700
• Leaf Aptus-II 5 digital back on a Bronica ETRSi

Images taken in RAW format, 14-bit with the Nikon, 16-bit (14 effective) with the Leaf, at the native ISO’s of 200 and 25, respectively.

RAW processor

Adobe Camera Raw 6.3.  The only controls used to vary the dynamic range of the images were Exposure (white point) and Blacks (black point).  White Balance was adjusted with the eyedropper, and perspective controls were used to straighten the texture target images.  All other settings were zeroed, including Brightness, Contrast, Sharpening, Noise Reduction, and Tone Curve.  Images processed full-size at 300 ppi for printing, 16-bit, in the Adobe RGB color space.

Why zero all the controls?  The default Brightness setting of +50, in my opinion, is much too bright to use as a default value; landscape images in particular often have much more dramatic skies at lower values.  And high Brightness settings are likely to raise the zone V (meter reading) values well above a midpoint L* (lightness) of 50.  I avoid sharpening and noise reduction in the testing workflow because I want to see the true noise and signal-to-noise ratios generated by the cameras’ sensors.  Zeroing the Contrast setting and flattening the tone curve is a more complex decision, as most images benefit from at least a little added contrast.  But the contrast S-curve has a large effect on the shadow values, as illustrated on the right.  I considered using a Medium Contrast Tone Curve setting in testing, but decided against it in the end.  Part of the reason is that I consider the images generated by Adobe Camera Raw to be “raw materials” that can be stacked and combined in the final image; even if the overall image needs a contrast increase, I want to see how much detail is available for use at the shadow and highlight ends of the RAW image.

Photo editor

Adobe Photoshop CS5.  Images printed at 300 ppi in the Adobe RGB color space.

Printer

Hewlett-Packard DesignJet 130 RIP, using HP Premium Plus satin photo paper.

Color management is essential to any print workflow.  The last step in profiling a printer, which is often overlooked, is the determination of the printer’s actual tonal range, using a test image like the one at the right.  (The thumbnail is a link to the .tif file.)  Until this is done, zone system calibration will be a frustrating experience, as determining the shadow and highlight thresholds will be a trial-and-error process.

To determine the printer’s tonal range, print the test image using the appropriate printer profile.  The image consists of a series of dark squares on a black background, and light squares on a white background.  The RGB levels of the dark squares run from 1 to 20, and the light squares from 254-235.  Let the print dry, then examine it in a good light, no brighter than the conditions under which your prints are likely to be viewed.  It should be fairly easy to identify the first visible light square, but the first visible dark square is something of a judgment call.  Many photographers act as though Dmax were sacred, and may recoil at the thought of printing at a level above the printer’s maximum black; but if you can’t see the difference between the darkest levels in a print, you have lost part of your image.  Choose the first dark square that you can really see.  The tonal range of the printer runs from the level darker than the first visible dark square, to the level lighter than the first visible light square.  Before printing any image, apply a Levels adjustment layer, and set the output levels to the printer’s tonal range.  (Tip:  save this as an action.)

One more step remains before setting out on zone system calibration.  Having determined the printer’s output levels, print another test image, this time to choose the threshold shadow and highlight levels (zones I and IX in the traditional system).  The image at the right is similar to the previous test image, but uses L* (0-100) rather than RGB (0-255) levels.  I chose 2 and 98 as my shadow and highlight thresholds.

Next:  the exposure series