Hereís an interesting experiment with the reproduction of the original luminance values in the print. Both 4 quad curves represent an average scene luminance range of 2.20 with one stop of flare. The negative, processed to CI 0.56 has a negative density range of 1.03 which closely matched the printís LER of 1.06.

The red highlighted reference line in the first example indicates the metered exposure which is at 12% reflectance. But notice how the original subjects tones at 12% reflectance become 18% in the print. The value of the metered luminance is lighter in the print.

4 quad - normal 12 percent.jpg Reproduction curve for 12 percent.jpg

Now, what would happen if something is metered slightly lighter than 12% reflectance like an 18% gray card and then printed it to a reflection density of 0.74?

4 Quad, 18 percent target.jpg Tone Reproduction - 18 percent keyed.jpg

The print tone matches the original luminance value, but not without a cost to the reproduction curve. Interesting enough, from what Iíve recently discovered, this curve looks similar to the preferred portraiture curve.