darkroom equivalent of "curves" in PS?

[paulr]

...There is no limit.

Or maybe there are no theoretical limits. In practice, some things are so hard to do that we tend to avoid them. Especially when working with color. It's very difficult to use photoshop to match certain kinds of color renditions that can be achieved with raw processing tools. And it's very difficult to get any digital tools to match the color rendering of certain color films, especially the greens of folliage.

I personally don't want my pictures to look like Velvia, but photogrphers trying to get the same palette with digital tools have a hard time ... especially with leaves and grass.

We more often hear the opposite argument ... that all the stuff we do in photoshop is possible in the darkroom. It is, and there's evidence going back to the mid 19th century. The question again is difficulty. Something that took hours for a studio full of trained brush artists can be done in minutes by anyone with a basic command of photoshop. What was previously a special project can now be part of a normal workflow.

[Andrew O'Neill]

Things I do to manipulate the film curve in the darkroom is choice of developer, dilution, over-exposure (in the field) under-development, bleach and redevelopment. Out in the field, pre-exposure...
For your cemetery image, I would probably use pre-exposure.

[gubaguba]

Curves per se doesn't exist in the darkroom. Back in the day we would use a sensitometer and plot the density response curve of films and papers. This is what photoshop curves is based on. However photoshop curve is not a curve at all but a flat line response, it curves when I change it. In the darkroom these curves (density) can be changed by changing exposure, developers, developer times, using toners. All of these need to be tested to be used properly.

[Drew Wiley]

Plotting densitometer curves is still a very useful skill when doing advanced color printing. I rarely bother in black and white work.