Digital Lith Case Studies 4

Digital Lith Case Studies 4
Published: Mon, March 2nd 2020

Originally published Sat, March 2nd 2019

Now, after the detour about the lookup table generator, we are back to bromide and sulfite, as promised in episode 3. Last time we went from the default values up to a higher amount of bromide. This time we go the other direction and will increase the amount of sulfite.

We will use the lookup table from the last episode, but I have inserted an additional value on the highlight side to make the paper base lighter. You can download the starter preset which includes the lookup table from here: Click!

IMAGE

OK, as always, here is an image we are going to work with, a reflection of Salem hospital in Heidelberg in a window of a parked car. It is straight out of the camera using the b&w jpg that the camera produced: Click!

Let us first develop it using the default values so that we have a base we can compare too. But let us develop with tray movement set to 75 because of the dark shadows at the bottom of the reflected building and increase exposure to a value of 1 because of the highlights at the back of the car. And to hold shadows a bit better we also decrease the development time to 95. Now did I do all that in one step? Certainly not. I first developed with the default parameters, then adjusted the exposure and tray movement and developed again and then went time traveling down to a development time of 95. I just invested some time so that you can save it. But you might want to do every single step one after another to get a better feel for the process. Make a long story short, this is what we get:

IMAGE

Now that we have a starting point. This time we go into the other direction and we start with a pretty strong increase of the sulfite which we set to 10 and since that cuts development time we will have to increase dilution. I went with a value of 50 and kept the tray movement as well as the exposure parameter as is but increase development time to 100 again.

IMAGE

What you can see. The image has less contrast and a lot less grain but still lith like and a lot more detail in the shadows. Look at that fence in the two crops below:

IMAGE

The above crops show that - surprise - with less and smother grain you preserve more of the details, although the image does not look as sharp. But let us ignore this and go even a bit further with the sulfite to a value of 20.

That means an increase of dilution up to 70 to keep at the development time of about 100. That high a ratio of sulfite/bromide smoothes out grain even more. Grain is now not that pronounced any more. Not very lithy.

IMAGE

Now in episode 3 we saw that we can smoothen the grain by adding negative bromide increase during the process (this is the same as if we would have been able to increase the sulfite during the process). In the next attempt on our image we are going to add grain back by setting the bromide increase to a value of 2. For that we have to decrease the dilution again. Otherwise we would need a much longer development time. We go for 50 and get the following result:

IMAGE

Looking closer at the grain we may even go with a bromide increase of 3 and dilution of 45 so the grain gets a little bit coarser and also the contrast will get increased bit more again.

IMAGE

You will get a better idea about what is going on by looking at the below crops. With the increased bromide we added some grain back to the image and also some local contrast. Here are the crops from the image without bromide increase and the image with bromide increase set to 3. Click on the image to get the enlarged image.

IMAGE

And that is it with our excursion into increasing the sulfite.

In the next episode we will have a closer look at the grain gradient parameter and its usage and will also learn about another totally different way of adding more grain to the image.