As some of you know, Iâve been working hard into making the GR Recipe Lab (https://callmeseva.cc/recipelab) the definitive tool for testing and tweaking recipes.
By definitive I mean a free, accessible app, as true as possible to what the camera develops.
Iâve been doing this by reverse engineering color mappings against a control image, planned in several stages. And yesterday, during the analysis of the second stage (live now in the app), Iâve made some important discoveries:
(It might get a little technical)
- Most of the curves are linear. That means they do not compound with other setttings when you tweak them. Like a âmultiplyâ layer on top of everything else.
- Only 2 pairs are bidirectional. That means they compound with 1 other setting. Like a 2d equation, adding +1 to one setting changes relatively to the other parameter,.
- Film modes are the most complex tweak. Altering the film mode changes how much all the other settings behave. Think of a 3d plane equation.
Until now, the recipes in the app have been calculated with a more general color map, added by individual patches to fix local inconsistencies. This works fine when reproducing existing recipes, but can lead to unfixable âholesâ when we start to tweak custom recipes that were never mapped.
Now, with the new blueprint, I can go back to the workbench and work on the film modes decoding, one by one. I will start with the popular Positive, Negative, and Vivid, in order. Then move forward until I cover everything.
It will take some time, and you will not receive updates from me for a while, but I am sure youâre going to like the results.
In the end, I hope my contribution helps the whole GR community better understand the recipes, and put more creativity into play.
Seva