Film curves and contact printing

[Mahler_one]

I intend to do some contact printing with my 8x10 negatives, using one of the graded fibre based papers. I have very accurate film curves for the new Tmax 400, Delta, and HP5 for use on my Durst 1200 with the color head and diffusion set up. I can use any of those films that is/are suggested.

I wonder if such film curves will produce negatives that are satisfactory for contact printing, or does one need to produce somewhat denser negatives for contact work? I'll probably be using Dektol-Selectol or Ansco 130 equivalent, and will probably use the light source that Michael recommends for azo-amidol work. Indeed, while asking the question it occurs to me that I also wonder about the "ideal" negative for Lodima-amidol work which I hope to begin shortly. Thanks for helping.

Edwin

 

[Jim Noel]

If you are going to contact print on enlarging paper, and it sounds as if you are, your curves should work. If you are going to print on a silver chloride paper, or any of the alternative process other than cyanotype you will need curves which produce more contrast, not more dense negatives. A correct negative for these processes is slightly different for each process. Greater contrast is indicated by a greater slope in the straight line section of the characteristic curve.

 

[Mahler_one]

Thanks Jim. Looking at my curves, would one simply develop for a slightly longer time?

Ed