[Cin] Again on plugins in floating point (HDR)

[Andrea paz]

In addition to what Andrew suggested, the easiest way to check whether
CinGG reads data above 0 - 1.0f is to use the eyedropper. On the white
parts of the image, if you have the clip you will always read the
fixed value 1.0. If CinGG also supports HDR data you will read values
above 1.0f, even though we still only see a pure white in the
compositor.
Another way is to open scopes and disable the "smooth" option. We will
see the values go beyond the 0 - 100 range.