Neg Density/scale

Discussion in 'Alternative Processes' started by clay, Nov 25, 2002.

  1. clay

    clay Subscriber

    Nov 21, 2002
    Asheville, N
    Multi Format
    Azo grade 2 in Amidol with no water bath yields an ES (exposure scale) of about 1.4 (e.g. prints a 1.4 density range (DR) on your negative) on a stouffers test wedge. With a water bath, you can get it to about 1.8-2.0. A palladium print on the same Stouffers wedge will yield an ES of about 1.8 to 2.1, depending on the paper used. However, if you develop your negs in a staining type developer such as ABC, Rollo Pyro, W2D2, or pyrocatHD, you will get actinic (UV)blocking stain in the highlights that conveniently knocks the target DR for palladium down to 1.4. Magic! So, if you use a staining developer, you can print your negs on either or both palladium and Azo. This is a neat benefit to these film developers. The big difference in palladium and Azo is in the curve shape. Palladium has a very long toe, so the midtones and highlights just seem to go on forever. However, the shoulder is pronounced, and getting good shadow separation and contrast is difficult. This shortcoming can be rectified through a gum over treatment, however. But that is another subject. Azo on the other hand has a very linear straight line response with much less of a shoulder and toe. Azo also has a longer reflective density range with a Dmax in the 1.7-1.8 range versus 1.35-1.4 in palladium. They have different looks, and it boils down to taste and personal esthetics. But the good news is that you will be able to easily switch horses midstream if you use a staining developer for your negatives.