Setting the Contrast
Taken together, these controls let you shape the overall contrast quite precisely. A couple of handy shortcuts let you keep the cursor on the image to read the RGB values while you adjust the controls. The Tab key selects the next field. The up and down arrows increase and decrease the values in the selected field by 1, while adding Shift changes the increment to 10. Here's my recommended step-by-step procedure:

1. Start by looking at the values in the white patch. Use the Exposure slider to match the values in your capture to those in the reference image.
2. Next, look at the two mid-gray patches (Row 4 Column 3 and Row 4 Column 4, respectively), and use the Brightness slider to adjust the values in your capture to match those in the reference image. If the patches are very far from neutral, take the middle of the three values as the aim point.
3. At this stage, the contrast should be in the ballpark, but the color balance may be wildly off. Set the white balance by clicking Camera Raw's White Balance tool in the second-to-lightest gray patch. This may change the tonal values in the mid-gray patches, so go back and readjust the brightness slider if necessary. Figure 5 shows Camera Raw's tool palette with the White Balance tool selected.
   
   

   Figure 5: The White Balance tool in Camera Raw's tool palette.

4. Check the values in the second-lightest (Row 4 Column 2) and second-darkest (Row 4 Column 5) gray patches. If the light gray patch is too light and the dark gray patch is too dark compared to the reference image, increase the value of the Contrast slider.
5. If necessary, fine-tune the values in the black patch (Row 4 Column 6) with the Shadows slider.

By this point, you'll probably have noticed that everything you do affects everything else. You may have to go through two or three iterations of these edits to get the best results. You probably won't be able to get as much tonal separation between the white and light gray patches as in the reference image. Don't worry -- it's OK if the white patch winds up being a little darker than in the reference. You should, however, be able to get within 5 levels or so on the remaining gray patches.

Before proceeding to the Calibrate tab, you need to make one more edit in the Adjust tab. Look at the values in the red (Row 3 Column 3), green (Row 3 Column 2), and blue (Row 3 Column1) patches, and note the red value for the red patch, the green value for the green patch, and the blue value for the blue patch. If your camera is at all typical, you'll find that the red value for the red patch is much higher than that of the reference image while the blue value for the blue patch is much lower. Don't worry. Concentrate on the green patch, and use the Saturation slider to make the green value for the green patch match that of the reference image. The result should look something like Figure 6 in terms of overall contrast, but the hues may be different.

Figure 6: The Adjust tab edits completed (top) and the settings used (bottom).