The "Tilt Shift" effect simulates depth of field in a much simpler (and more performant) manner. Instead of blurring based on the depth buffer, it simply blurs everything except for horizontal stripe on the layer. The effect is controlled by the properties:
Focus Position- the vertical placement of the center of effect (the 'focused region') on the screen, from top to bottom.
Focus Width- the vertical size of the in-focus region.
Blur Amount- how much the not-in-focus regions are blurred.
As with the Depth of Field effect, this effect has a
Debug Rendering option that you can enable to see where the blur will be applied to the Layer. (See above for further description.)
Available under certain Qt licenses.
Find out more.