Gradient used to mimic neutral density filter along horizon

[Ofnuts]

(12-26-2018, 12:13 AM)mholder Wrote: Without pictures this is kind of difficult to understand for me.
Maybe use the pencil/pen tool and paint with the gradient setting in the dynamic options,  or create a path and stroke it with pen/pencil using the tool setting.

• In the example below, I assume the "sky" layer in on top
  
• Enlarge the canvas by at least the width of the transition you want (you'll understand why later in the process)
  
• Create your selection on the "horizon" (it should extend out of the layer and encompass the canvas)
  
• Select>Grow by half the width of the transition
  
• At a layer mask to the sky layer
  
• Set the gradient tool to Shaped, spherical
  
• Adjust the gradient on-canvas so that most of the color change is around your sky/ground border