DOP quick explaination:
go to the viewport you wish to render from.
Go to the top menu item Display>Heads up display> and check 'Object details'. This will list, among other things the distance of the object from the camera.
Go to the window menu and pick View>Select camera then cntrl A to get the Attribute editor. Scroll down to Depth of Field and check the selection box.
Play with the attributes until you get a satisfactory result
The first part should take 2 seconds. The second part is the creative bit and it may take a very long time to get something that looks like you imagine it. It does for me anyway.
Nice work on the character
Check out the subsurfacescattering on my tongue...
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