Add weather or lens flare effects using the Atmosphere menu.
This menu offers two sections, which can be used independently or together: Weather and Lens Flare.
To begin adding an atmospheric effect, drag the relevant opacity slider. This will now display a drop-down menu from which you can select your effect. To add your own effect, click “Add…” and choose the desired image from your computer.
Resize the atmosphere effect by scrolling with the mouse wheel or using a two-finger scroll on a track-pad.
Position the atmosphere effect by clicking and holding the left mouse button and dragging the mouse pointer.
Click Flip Weather or Flip Overlay to flip the atmosphere effect image horizontally.