Hi, do you and Stephen mean finding the film and paper values using a densitometer (or densitometers)? Thanks.
Hi ypkennedy!
First off, I applaud your ingenuity and originality. I like the fact you start with the Stouffer scale.
Densitometers used to cost thousands of dollars, but now are relatively cheap. That's good, but what's bad about the available used densitometers is that you take a bit of a risk... It might not work. There's a popular model where its replacement light bulb is hundreds of dollars. That's silly.
I have a Macbeth TR-524 densitometer that cost me not much more than shipping. It's electronic and I worry one day it will just not power on. But it works now and I can get bulbs for it at my local Ace hardware store. To back that up, I have a Marshall Studios densitometer. It's a visual densitometer based on the law of inverse squares. It uses an ordinary light bulb that travels back and forth. There is nothing that can go wrong with that.
Anyway so long as the Macbeth works, I have reflected-light and transmitted-light modes and I can read the densities of my film and paper quickly.
A little time spent plotting graphs gives me sensitometric curves to work with. Like you, I have a derived chart (Time-Contrast Index) for film, so I can quickly decide how much development I want to give a particular sheet or roll of film... based on the original scene.
Don't read too much into my criticism that "it seems wasteful not to use densitometry".
The "waste" I mention is that you may have inconsistent outomes of "speed" because you are evaluating the resulting print visually.
I might shoot my film at the same "speed" as you. But I know the film speed is its ISO speed, and I'm choosing a different speed to get the quality I want...
While you are looking at the quality you want and picking the speed that gives that to you.
Not sure there is any difference, so I say not to read too much into my critique, because I know you'll get excellent results.