At the top of each processing module is the module header.

Click on the module name to expand the module and display the parameters that control its operation.

By default Ansel will only allow one processing module to be expanded at a time – if you click the header of another module, the previously-opened module’s controls are collapsed. If you want to expand more than one module, you may expand further modules by Shift+clicking on the header and all previously expanded modules will remain open. This behaviour can be reversed via a setting in preferences > darkroom.

Note: Expanding a module does not cause it to be activated. See below for how to activate modules.

The module header contains the following controls in order from left to right:

on/off button
Click to toggle the module on or off. Some modules are essential for image processing and cannot be disabled (though their parameters may be amended). Similarly, some modules are not applicable for certain types of image and cannot be enabled.

Ctrl+click on the on/off button to toggle whether the module has focus. The focus state is usually used to activate any overlays that a module places over the image to control its functionality. For example, the crop module only shows the composition and crop guide lines on the image if it has focus. Modules are automatically given focus when expanded.

module name
The module name consists of a description of the module’s operation (which cannot be changed) followed by the module’s instance name (which can). By default the first instance of a module has an empty instance name. If you create additional instances, the name of each new instance is initiated with a unique integer. For example, the second created instance of an exposure module will be automatically named exposure 1.

Ctrl+click on a module’s name to manually amend its instance name.

mask toggle
This icon will appear in the header whenever a mask is active on a module. Hover over the icon to see what type of mask is enabled. Click it to display the current mask as a yellow overlay over a black-and-white version of the image. Solid yellow indicates an opacity of 100%; a fully visible gray background image (without yellow overlay) indicates an opacity of 0%. This toggle button can be disabled in preferences > darkroom > show mask indicator in module headers.
multiple instance menu
This menu allows you to create, delete, move and rename module instances. Right-click on this icon to directly create a new instance of the module. See the multiple instances section for more information.
Click to reset all module controls to their default values. Ctrl+click to reapply any automatic presets for the module – if no automatic presets are applicable for this module, Ctrl+click will simply reset to default values (same as click).
presets menu
This menu allows you to apply, create and edit module presets. See the presets section for more information.

The visibility of the four icons to the right of the module name can be controlled in preferences > darkroom > show right-side buttons in processing module headers.