Replacing Skies – (Difficult Subjects e.g. Trees) by Paul Topham

In this workshop, Paul will explain a method of replacing skies around difficult subjects

Replacing Skies

Open image
Select ‘Channels’
Pick image most contrasty, e.g. Blue or Red (Highest degree of contrast).
Select ‘Image’ (from menu)
Select ‘Calculations’ from dropdown.
Source 1 = Background
Channel = Blue or Red (see above)
Source 2 = Background
Channel = Blue or Red (see above)
Blending = Overlay
Mask = unticked
Result = New Channel
OK.
This creates a new alpha channel – “Alpha 1” under the blue channel.

Menus
Image, Adjustments, Levels (or CTRL + L)
Move arrows -> & <- until foreground is black and sky is white.
OK.
Paint over any holes in foreground with a black brush.

Menus
Image, Adjustments, Invert or (CTRL+i)

(CTRL +) while clicking on the Alpha Channel to create a mask.

Click on RGB Channel.

Click on Layers Tab

Now drag your image using the move tool (V) onto a new background image (sky). Holding down the shift key will make the two images fit together in unison.