In painting, atmospheric perspective refers to the technique of creating an illusion of depth by depicting distant objects as paler, less detailed, and usually bluer than near objects. This comes from observing that light, color and contrast behave differently when looking off into the distance. Steve Arnold in a YouTube video shows examples of painters employing atmospheric perspective. He goes on to demonstrate using a Photoshop Neural Filter to generate channels for near and distant parts of an image.
Based on his video, I have created a Photoshop Action to generate these channels, named Depth Map. Download the Selections.atn file; double-clicking on it should load the actions into Photoshop. You will need to be running the latest version of Photoshop 2024 and have the Neural Filter “Depth Blur” enabled (this currently is in beta).
When run, the action creates a Depth Map layer generated from all visible layers, placed at the top of the layer stack and hidden. Of greater utility the action creates two new channels in the Channels panel, Distant and Near. To add a sense of depth, use them to mask Adjustment Layers for light, color and contrast. And once created the mask can be edited to further tweak the adjustment. The channels can be used to mask layer groups as well. For example, one could reduce clarity using a group of adjustment layers, apply a Distant channel mask to limit the effect to objects that are off in the distance.
What about the hidden Depth Map layer? The Distant channel was obtained by applying a “Lights 1” luminosity mask to the (hidden) Depth Map layer. And the Near channel by using a “Darks 1”. You can create more constrained versions of the channels by using alternative luminosity masks once you make the Depth Map (temporarily) visible.
By way of demonstration I lightened the far hillside by masking a Curves adjustment layer with the Distant channel mask.
