Simulating depth of field with Gaussian Blur

- In this movie we're going to create…a kind of depth of field effect…using Gaussian Blur combined with layer mask…and it should allow us to better focus our attention…on the bearded fireworm.…So I'm gonna start things off by once again…creating a merged copy of the entire composition…by pressing ctrl + shift + alt + e,…or cmd + shift + opt + e on the Mac.…And I happen to know what I'm gonna do with this layer…so I'll go ahead and name it GBlur 6,…because that's the radius value that I intend to use.…

And then I'll go up to the Filter menu,…choose Blur, and choose Gaussian Blur.…And now I'll go ahead and enter that Radius value…of 6 pixels, you can of course go your own way,…but that's what I came up with.…And then I'll click OK.…Alright, now we don't want the entire image…to be blurry, of course,…so I'm gonna start things off by masking the effect away.…And so rather than clicking on the Add Layer Mask icon,…I'm gonna press the alt key and click on it,…and that way I'm adding a black layer mask,…so everything about the blur effect is hidden.…