In your post re Ferric Oxalate you wrote:
>I have just tested them by coating one piece of paper with enough solution from
>each batch, with pd, for a step wedge. The paper was exposed under a UV lamp
>for twenty minutes. All recent batches exposed to between steps six and seven
>on the step wedge and the 1994 batch to between steps 4 and five.
>
>All developed out to between 15 and 16 including the 1994 batch.
I would infer from this that the total visible steps are 9 for the recent
batches and 10 for the 1994 batch. The 1994 batch would be able to handle a
slightly contrastier negative. What I cannot determine is the density
ranges these formulas can handle. If you used a 21 step wedge with a
density range of 3.05 (.15 per step) then your formulas need negatives with
a 1.35 and 1.50 density range respectivly.
Terry, am I misreading your results?
Mike Robinson
Toronto, Canada