Ok. First I would like to demonstrate if I have understood the new approach.
When I use Fimic RGB, I have followed your advice and accordingly I get the best results if I first set the medium grey in the exposure as I want it (without consideration of the overexposure) and then use Filmic RGB.
I’m going to take an example now, so that there’s not too much abstract talk.
- In this photo I first adjusted the exposure so that the trees are well lit:
- Then I used Filmic RGB to adjust the dynamic range so that the details in the snow can still be recognized to some extent. And as the histogram shows, I still have enough space for further processing. However the image is very flat and diffuse which is normal as a result of the strong compression:
- Now comes the tricky task of emphasizing the details without affecting the dynamic range too much. Here you suggest to use a local contrast module. Although this will actually help to increase local contrast a bit it is not enough and there is a risk that you will either over-sharpen the image or get other unwanted effects. Note that the snow has not yet gained much in local contrast:
- So we have to bring the highlights back more to work on the details. For this purpose tone equalizer is a very good choice. The masking of guided filter can be a bit cumbersome, but after a little effort you get good results. Now you can slowly see the footsteps in the snow:
- Now we use the RGB curve to increase the details in the snow. I found this to be a difficult task, as it works differently than the normal curves in darktable. Even very small movements of the points can cause big changes in the image and it is not easy to get a reasonable contrast in the medium grey area. The presets show the way but it is quite tricky when you have to do something yourself. In this example I did not use the “compensate middle gray” option because it gives me more space. Now the footsteps are clearly visible:
- So, as far as details in the snow are concerned, we are almost there. I have found that in certain situations Haze removal module is very suitable for highlighting the details and is even much better than local contrast module. However, it tends to create the halos and you have to protect the shadows. In this case it has served well:
- Details are now very nice, but - as you can see in the histogram - the steps have also resulted in some shadow areas being a bit underexposed. I’ll be happy to brighten up the image a bit now without losing the details in the snow again. I found this very difficult. Both the exposure and the curves have caused the details to disappear. The best solution was to go back to Filmic RGB and move the middle grey luminance to the left and after that add a bit contrast with color balance:
After I increased the saturation with velvia, vibrance and color balance modules, the picture finally looks like I wanted it to. Now, not only the footprints are recognizable but also the fine texture, colors and diffuse shades in the snow:
I intentionally took this photo because you can clearly see how important it is - besides the dynamic range compression - to have enough space and possibilities to handle the details in shadows middle gray but also in highlight areas.
This article is much too long, in the next one I will make a few remarks.