Rawtherapee tutorials
Please note that the recent game-changer tutorials are only available on the rawpedia.pixls.us link and not on the rawpedia.rawtherapee.com link.
The rawpedia.pixls.us entry not only contains the tutorials which have already been posted on this forum but also a summary of the guiding principles for the new workflow, which can be broken down into four main steps:
- Raw data optimization ;
- Equalization and pre-tone mapping ;
- Tonal contrast adjustments and output tone mapping ;
- Color adjustments taking into account scene and viewing lighting conditions.
@Lawrence37 : Can you take this information into account for the 5.13 update?
@patdavid : Can we hope for clarification from the websites?
Thank you both.
Complicated or complex: a few additional comments
What is complicated refers to what is difficult to understand unless you are an expert in the field. A complicated project can be accomplished by breaking it down into clearly defined tasks and functions. There is a clear cause-and-effect relationship. In a complicated world, there is a standard, a plan, a reference point - something that serves as proof and allows us to distinguish between truth and falsehood. For example, in Rawtherapee, the graphical user interface (GUI) tools can seem complicated because they are often scattered throughout the interface, numerous, and use names unfamiliar to users (e.g., Wavelets, Retinex, etc.).
Complexity refers to a system whose behavior is more or less unpredictable because the nature of the multiple interactions between the systemās elements lacks stable cause-and-effect relationships. In RawTherapee and other software, this means attempting to solve a problem where the number of unknowns is greater than the number of equations: there are almost infinitely many solutions, which depend on numerous, more or less interdependent factors. These include the nature of the image (landscape, portrait, etc.), shooting conditions, the type of photographic equipment, the photographerās skills, the developerās skills, and so on. Faced with this diversity, the tools react differently, and the expected results are not always achieved.
The thread āItās not complicatedā¦ā provides an overview of the concept of ācomplicatedā. Other free software has reduced the ācomplicatedā aspect, but has it reduced complexity?
Itās not complicated
I will try in a few lines to present in a little more detail the foundations of āGame changerā and the choices I made. In other words, how to reduce complexity in Rawtherapee (these choices for dealing with complexity stem from systems thinking - systemic).
The tools of photographic systems.
Rawtherapeeās āCompetitorsā Software:
In Rawtherapeeās ācompetitorsā software, the concepts of ālinearā, āScene Referredā, and āDisplay Referredā are used; āLabā is rarely used. Associated tools are often āFilmicā, āSigmoidā, and āAgXā, typically located towards the end of the process and frequently utilizing primaries.
This introduction is not intended to be āgoodā or ābadā but rather to establish a vocabulary and some principles familiar to users.
The RawTherapee System:
RawTherapee uses slightly different principles:
Rather than using āScene Referredā, RT uses the concept of āSensor Referredā, and instead of āDisplay Referredā, the term āViewing Conditionsā (associated with āScene Conditionsā) is preferred.
āSensor Referredā encompasses the entire Raw process and virtually all the parts of the process (whose order is fixed in the pipeline) that take place in the āWorking Profileā. In āSensor Referredā, RGB, XYZ, and Lab data can coexist. It is in this area that āWhite Pointā and āBlack Pointā are calculated, just before being used, and the data range is limited to the dimensions of the āWorking Profileā. It is also in āSensor Referredā that the color gamut is compressed to make it compatible with the output profile. The general principle is to perform āWhite Balanceā and āPre-tone Mappingā as early as possible in the pipeline to ensure long-term data accuracy. These actions and principles are possible because all calculations are performed with real numbers in single or double precision.
Only then, at the end of the āSensor Reffreredā process, are the contrasts, local contrast, and colors fine-tuned to achieve a visually appealing image. It is at the very end ā āCIECAMā is recommended for this task ā that the colorimetry is fine-tuned to adapt it to the āviewingā and āsceneā conditions. Indicators for gamut overshoot and/or saturation allow the user to make any necessary adjustments to the initial settings. This step is the final one before converting the profiles to the output (screen, printer, TIF/JPG files).
Jacques
