Footage in the RGB Color Space
When super-white Y´C
B
C
R
values are converted to RGB, any values above 235 are
mapped to 255. Any variation in luma above 235 is therefore clamped, or clipped,
resulting in solid patches of white where there was once detail in the bright parts of
the image. If these RGB values are converted back to Y´C
B
C
R
, all white values of 255
are mapped to a single value (usually 235, which is white in Y´C
B
C
R
). The newly
converted white values are lower than the white values originally captured, causing
areas of the picture that had super-white values to darken slightly and to appear flat
where there was once detail in the highlights. This is known as luma clamping. You
can avoid this by editing your Y´C
B
C
R
footage natively in the
Y´C
B
C
R
color space.