I second your suggestion of using The View Camera Store to do testing. I've made the same suggestion here many times. They do it faster, easier, and likely for less money while providing more information than one spends doing their own testing. That said, doing one's own testing is an excellent learning tool.
I'm not aware that "the digital world is supposed to make things easy." In my experience scanning and printing digitally makes things harder (but potentially better).
Before you criticize someone, walk a mile in their shoes. That way when you do criticize them you'll be
a mile away and you'll have their shoes.
Particularly: The meaning of contrast index, in terms of normal values, for people who did not read the BTZS book before reading the article on Pyrocat.
Rick "who actually had to look at the Wikipedia article on sensitometry to understand the log-exposure axis--every 0.3 is a stop" Denney
To be clear, a contrast index of 0.5 is normal for printing with Silver Gelatin.
On the BTZS charts, the Contrast Index is listed as G with a bar over it, which means Average Gradient. It's the average slope of the contrast curve. In other words, given a certain amount of exposure, how dense the negative becomes. When contrast is low, even a lot of exposure gives little density, and the curve is rather flat: its slope or gradient is low. When contrast his high, even a little exposure results in a lot of density: the slope of the curve is rather steep, IE the gradient is high.
Actually, Sandy's article has a table - at the top of the same page to which I have referred - which shows the recommended Contrast Index for different media.
That table is another piece of information which is worth its weight in gold, as is the statement "Most processes have means to control contrast but it is good practice to always start with the best negative possible for the process."
Visit pyrocat-hd.com for the suggested development times.
16 minutes could be too much, depending on agitation. The negative should look "thin".
TMX is a great film.
You should look at the pyro developers/negatives as a "variable contrast developer/negative". Scan them in color and pick the channel closest to the target contrast.
Last edited by Ken Lee; 26-Mar-2012 at 16:58.
For discussion and information about carbon transfer please visit the carbon group at Yahoo.