There is another possibility here. Pre Exposure. This is expolsing the negative to a surface of uniform luminousity before making you omage, which can be done with any camera that has a double exposure feature.
The following exposure zones have the following luminousity factors.
Zone 0 = 1/2
Zone I = 1
Zone II = 2
Zone III = 4
Zone IV = 8
Zone V = 16
Zone VI = 32
Zone VII = 64
Zone VIII = 128
Zone IX = 256
Zone X = 512
If you preexpose a flat surface such as a wall or some other object with little texture and uniform luminosity then meter the surface and expose your negative placing it on Zone II (three stops down from the meter reading as this will be a Zone V/18% gray reading). Then expose your subject with NO ADJUSTMENTS to your exposure meter reading.
Now Zone II has a luminousity effect of 2. When applied to the scale above, you will see the effect of Pre Exposure.
Zone 0 = 1/2 +2 + 2 1/2
Zone I = 1 + 2 = 3
Zone II = 2 + 2 = 4
Zone III = 4 + 2 = 6
Zone IV = 8 + 2 = 10
Zone V = 16 + 2 = 18
Zone VI = 32 + 2 = 34
Zone VII = 64 + 2 = 66
Zone VIII = 128 + 2 = 130
Zone IX = 256 + 2 = 258
Zone X = 512 + 2 = 514
According to this preexposure of the negative to a uniformly lighted surface that is exposed on exposure zone two will seriously raise the lower values in the negative (Zone I up to almost Zone III, II to III) while not affecting the higher values (zones V-X show little effect). Practice this as another means of control.