December 21, 2025

Legacy Modules & Their Modern Alternatives

Darktable is developing rapidly. What was “best practice” three years ago is often considered obsolete today. The reason for this is often the switch to a Scene-Referred Workflow. This new approach ensures more natural colors, better highlight recovery, and fewer artifacts (such as halos).

Darktable has two main pixelpipe workflows: display-referred (the old, “legacy” workflow) and scene-referred (the “modern” workflow). Each workflow relies on some of the same modules but also some modules are distinct to each workflow. The modules used solely in the “legacy” workflow (display-referred) we call “legacy” modules.

Additionally, some modules are no longer supported by darktable in any workflow, and these are called “deprecated” modules (a list of those modules are found in darktable’s manual on processing modules).

So that you don’t accidentally use modules that may degrade your image quality while using the scene-referred workflow, here is an overview of the “legacy” modules and what we focus on instead while teaching you the basics.

1. Sharpen

This is the classic “Unsharp Mask” (USM) known from the past.

Why avoid?
It greatly amplifies image noise and quickly creates ugly bright edges (halos) on contrasting edges. The result often looks “digital”, artificial, and over-sharpened.

The modern alternatives:

Today we have three tools that can do this much better:

1. Capture Sharpening:
   • What for: The absolute basis. It retrieves the details lost through the sensor filter.
   • Advantage: Extremely simple (usually just on/off) and low noise.
   • Note: Because it is more subtle, it can often appear as if nothing happened unless you are zoomed in.
2. Contrast Equalizer:
   • What for: To make structures and textures crisper.
   • Advantage: Very intuitive to use and creates no halos.
3. Diffuse or Sharpen:
   • What for: The high-end solution for perfectionists.
   • Tip: Use the preset “Lens Deblur” here. It physically calculates the blur out correctly instead of just overdrawing edges.
   • Note: It is a more technical module but many users achieve excellent results with it.

2. Shadows and Highlights

Formerly the standard tool to brighten dark areas and darken bright ones.

Why avoid? In the modern workflow, it often leads to dull images and local loss of contrast. In addition, halos quickly appear around objects (e.g., trees against a bright sky).

The modern alternative: Tone Equalizer.

It is more powerful, preserves local contrast better, and avoids halos almost completely. Operation via the “cursor in image” is also very intuitive.

3. Base Curve

For a long time, the module that gave the RAW image the typical “JPEG look”.

Why avoid? The base curve often blows out highlights too early and makes colors in bright areas pale (Hue Shift). It works “display-referred” and clips data that we might need later.

The modern alternative: AgX (or Filmic RGB, Sigmoid).

These modules gently map the camera’s huge dynamic range to your monitor without destroying colors. Sigmoid is often easier to use and delivers crisper results “out of the box”.

Starting with DT 5.4, AgX is the best choice.

4. White Balance – Partially

Attention: The module “White Balance” is still needed, but differently!

The change: In the modern workflow, you only set the “White Balance” module to “Camera reference” (often standard).

The modern alternative: You make the actual creative adjustment (warmer/cooler) in the module Color Calibration. It offers much more powerful tools for color adjustment (CAT) and handles difficult light better.

5. Local Contrast

Status: Conditionally recommended.

What is this about?
This is not about light/dark (AgX does that), but about structure and clarity. The module is supposed to make the image “crisper”.

Why be careful?
If not careful, the module can give rough results and quickly creates unnatural edges (halos).

Our suggested alternatives:

1. Contrast Equalizer:
   The king of structures. Here you can decide specifically: Do you want to sharpen the finest details or make rough shapes more plastic? This gives you much more control without side effects.
2. Diffuse or Sharpen:
   The preset “Add local contrast” ensures extremely clean, fine structures and gives the image the finishing touch that AgX alone often does not deliver.

Summary: Your Modern Toolbox

Now that you know what to avoid, what can you use instead?
If you are new to darktable (or switching), concentrate on these “Big 5+1”. With these, you cover 95% of your edits – faster and with better quality:

1. Exposure: Control brightness (midtones).
2. Color Calibration: The modern white balance.
3. AgX (or Sigmoid): Tame contrast & dynamic range.
4. Tone Equalizer: Brighten shadows, recover highlights (without halos!).
5. Color Balance RGB: Saturation, color grading & brilliance.

+1. Sharpness & Details (Optional):
At the very end, when the look is set.

• Capture Sharpening (in RAW)
• Contrast Equalizer or Diffuse/Sharpen (for the “Pop”)
• Denoise

What’s next?
How to use these modules in the correct order and how they work together, you will learn step by step in the next chapter: Standard Workflow

Why we advise against these modules

Darktable prides itself on its backward compatibility. This means: Even modules developed 10 years ago are still there today so you can open old edits.

But: Many of these modules (often called “display-referred”) work according to logic that no longer fits the modern, more physically realistic workflow (“scene-referred”).

If you mix these old modules into a modern editing process, it can lead to problems:

• Halos (light fringes) around edges
• Unnatural color shifts
• Loss of image information in bright areas

Our philosophy on darktable.info:
We want to show you the best possible, future-proof way. That’s why we mark these modules here as “Legacy” or “Not recommended”. Experienced professionals may use them for special effects – but as a beginner, you may make life unnecessarily difficult for yourself if you use them.