Compositing CGI with Bigger Node Trees - Nuke 101: Professional Compositing and Visual Effects - page 130

Next,addalittle softening totheSpecular pass.You'regoingtouseablursoyou
need to do this before the Unpremult operation. Remember: Always apply filters
to premultiplied images.
8. Move Unpremult5 to the left to clear up some room between it and the Spc pass
Shuffle node (should be Shuffle5).
9. Insert a Blur node after Shuffle5 by pressing B on the keyboard.
10. Change Blur1's Size property to 2.
To make the Specular pass a little less apparent, use Merge4's Mix property to
mix it back a little.
11. Make sure Merge4's (the Merge that's adding the Specular pass) Properties panel
is open by double-clicking it.
12. Bring down the Mix property to a value of around 0.6.
The specular pass is softer now and sits better with the other passes. The specular
part of your tree should look FIGURE 3.45 .
Figure 3.45. The Specular pass branch.