How do I invert the lens blur effect

[Nick Fawbert]

I have a very crisp photo of a long narrow room, taken at an angle with the far corner in the centre of the image with a very narrow aperture.

I want to use it as a back drop for a green screen video where the speaker is sharp, centre of the image.

That means I need the sides slightly in focus, but the centre blurred because it is much farther away.

Every tutorial is about getting the centre in focus, and the sides blurry. I need the opposite.

What’s the way I do this?

[davescm · Accepted solution]

Try the Lens Blur filter with a depth map

To do that :

Add a layer mask revealing the areas you want to blur - remember a layer mask can be a gradient not just black or white

Go to Filter > Lens Blur

In depth map select  "layer mask"

Adjust the blur

Hit OK

Disable the layer mask

Dave

[Nick Fawbert]

Thanks Dave

That gradient layer mask sound interesting - I shall try and find a tutorial  

[Nick Fawbert]

Excellent Dave, right answer, perfect.

If you want to see it in action in all its graduated beauty you can see it in the background here: Mutiny Interview Nick Fawbert February 2018 1080p on Vimeo