[markbarendt]

What I'm interested in is the character, or "feeling", of films. I don't have any specific scene in mind and I'm not searching for a suitable film for a purpose, I want to see what this elusive "character" is simply out of curiosity. If different films have different character, there must be a difference, if subtle, in the final image. Is it the spectral sensitivity? Contrast? Latitude? I can read about differences and kind of understand descriptions of a film's properties, but it's so much easier to understand with two pictures side by side.

Of course many other things can change the final result, which is why I was trying to say "don't change anything except the film". Difficult, certainly. Perhaps sending the films to a pro lab would make it easier to ensure consistent development?

I'm actually going to say that taking the developer out of the equation and matching CI may be a mistake.

For example TXP and HC 110 are complimentary, the film and the developer naturally lean toward the same type of curve, a long beautiful toe and great separation of tones middle to high. It is a classic combo. TX/HC110 similarly.

Delta or TMax in DD-X or TMax developer will have a shorter toe, better separation in the shadows, but the straight line may actually be slightly flatter, so the mid to high tones might look flatter, if developed to the same CI. These are "classic combos" too.

Adjusting the CI to match the "snap" in the mid to high tones of TXP/HC110 or some personal best CI would provide a more practical result, a better demonstration of character.