Creating Looks - The Art and Technique of Digital Color Correction - page 455

Pete Jannotta takes on the Artbeats scene of the Marines ( Figures
10.101 and 10.102 ) to attempt another day-for-night shot.
Jannotta goes straight to secondaries to try to select the sky. He picks a
spot that selects the left side of the sky, then widens the qualification with
the HSL selection sliders, grabbing almost the entire sky. Switching the
HSL selection so that it used only luminance improved the qualification.
Jannotta thinks this selection will be good enough, but it isn't, because
as he brings down the luminance in the qualification, it brings down the
right side of the sky before it brings down the left side.
Fig. 10.101 Source image
courtesy of Artbeats.
Fig. 10.102 Tektronix
WVR7100 screengrab. Upper
left: RGB Parade. Upper
right: vectorscope. Lower
right: composite waveform.
Lower left: RGB Parade
zoomed in 5x to the blacks.