Drag the black triangle associated with This Layer to the right
until the space around the moon turns invisible, as shown in
Figure 5-54. I find this happens when the first numerical value
reads 50, meaning that any color with a luminosity level of 50
or darker is hidden.- Add some fuzziness. The problem with the current solution is
that it results in an abrupt transition between visible and invis-
ible pixels. (If you zoom in on the left side of the moon, you’d
see what I mean.) To soften the drop-off, you need to add some
fuzziness. Press the Alt key (Option on the Mac) and drag the
right side of the black triangle to split the triangle in half. Then
drag to the right until the first This Layer value reads 50/105
(again, see Figure 5-54).
Figure 5-54.
Here’s what the 50/105 values mean:- Any color with a level of 50 or darker is invisible.
- Any color with a level of 105 or lighter is visible.
- The colors with luminosity levels between 105 and 50 taper
gradually from visible to invisible, respectively. This is the
fuzziness range.
The effect looks slick but not very realistic. The moon appears
to be sitting on the sky instead of sunken into it. Part of the
problem is that the moon is in front of the clouds. Fortunately,
the Underlying Layer slider lets us push the clouds forward.
Masks, Knockouts, and Luminance Blending 163