December 6, 2025

The Exposure module is the first and most important step in your editing. Here you lay the foundation for everything else.

In the modern Darktable workflow (scene-referred), this module has a very specific task: It defines the brightness of your midtones (your main subject).

It is not there to rescue blown-out highlights or brighten deep black shadows – later modules like AgX, Filmic, the Tone Equalizer or Color Balance RGB take care of that.

The most important sliders

1. Exposure

This is the main slider. It works in Exposure Values (EV).

• +1 EV means: The image becomes twice as bright (like one stop more on the camera).
• -1 EV means: The image becomes half as bright.

How to use it correctly:
Look at your main subject (e.g., a person’s face). Move the slider so that this subject looks correctly exposed. Ignore whether the sky in the background might become too bright or blow out. We will take care of that later in tone mapping (AgX).

2. Black level correction

This slider defines when a pixel is considered “pitch black”.

• Recommendation: Keep your hands off it! Darktable automatically reads this value from your camera’s RAW data. Manual changes often lead to washed-out colors or color casts in the shadows. Only change this if you know exactly that the automatic detection failed (very rare).

The Automatic (Pickers)

The module offers very powerful automatic functions, which you can access via the dropper icons to the right of the slider.

• Picker (Midtones): Click on it and then draw a rectangle over an area in the image that should have medium brightness (e.g., gray asphalt or skin tones). Darktable automatically adjusts the exposure so that this area lies perfectly in the middle of the histogram.
• Clipping threshold: This value under “Mode: Automatic” determines what percentage of pixels are ignored during automatic adjustment (to avoid taking extreme highlights as a reference). The default value is usually good.

Avoiding common mistakes

1. Fear of the histogram:
   In this step, the histogram is allowed to “hit” the right side (highlights blow out). That’s okay! Since we are working in a 32-bit floating-point environment, this data is not lost. The AgX or Filmic module will retrieve these details later.
2. Camera exposure correction:
   Sometimes you see that the slider is not at 0.0, but e.g. at +0.5. This happens when Darktable automatically accounts for your camera’s ISO sensitivity or exposure compensation. This is normal.

Summary

• Use this module as Step 1.
• Focus only on the midtones / the main subject.
• Ignore warnings about overexposure at this stage.