In this Selective Focus tutorial i will show two examples for depth map creation [Shallow depth of field effect] for landscapes and portraits.
First duplicate background layer. [CTRL +J]
click quick mask icon [Q}. Now select gradient tool. [G]
Choose linear for blurry feather edges.
Now drag the gradient tool on subject to focus.
Now exit quick mask mode to get selection.
Now goto channels and create new layer for depth map.
renaming layer – selective focus.
fill the selective focus layer with white to get mask selection.
i will use this layer as mask with lens blur filter.
Deselect selection [CTRL + D] keyboard shortcut.
Make sure selective focus layer invisible and rgb channel visible.
Now apply lens blur filter.
keep depth map source to selective focus [which i created earlier in step 2].
we can adjust blur radius but i’m happy with the depth of field.
here is before & after results
you can use this method to make selective focus on any photograph.
Tip:instead of linear gradient use radial gradient shade for portraits.