Ed, I agree, the problem is that while Azo is sensitive to UV when purer forms of UV are utilized the paper exposes more rapidly (too rapidly in most cases for effective burning and dodging).
Originally Posted by Ed Sukach
I have thought that perhaps a lower output UV source might really be beneficial for Azo. The primary reason would be that the proportional stain that Pyro developers impart to the negative act as additional density to blue light and also additionally to UV light as well.
In the case of blue light the Pyro stain may add the equivalent of appr. .20 units of density at a silver density of 1.20. Effective blue light transmission density then becomes 1.40.
The proportional stain adds additional density beyond the blue light effect to UV transmission. In the case above, for example, it may add another .20 density units to UV transmission. Effective UV transmission density may then be on the order of 1.55 to 1.60.
As the negative silver density increases the proportional stain effect to both blue and UV transmission increases.
The reason that I think that a lower output UV device may be beneficial to Azo users is that it would enable greater expansion of the contrast range of the camera negative then what reflector floods or even plant lamps would enable. Lower contrast films would then perhaps be more useable for Azo. Certainly all films would exhibit the ability to expand density range beyond what the blue light effect alone would be when using proportional staining pyro developers.
With your experience in this field, Ed, I imagine that you have ideas on how to effect UV usage albeit at a more manageable level. I would appreciate your thoughts on this. Thanks for your input.