User Manual

Table Of Contents
Accessing Extended Highlights and Shadows
Increasingly more productions are capturing out-of-range images thanks to digital cinema
cameras like the Blackmagic URSA Mini Pro and even the Pocket Cinema 6K camera. These
cameras capture very high dynamic range RAW images and maintain color detail even in
heavily over or underexposed frames. The extended white color detail can also give very nice,
natural results when blurred, glowed, color corrected, or even just when faded or dissolved.
While it is possible to work with these RAW images using integer data, doing so results in the
loss of the extended range values, losing all detail in the highlights and shadows. Float
processing makes working with logarithmic RAW images considerably easier by preserving
highlight and shadow detail.
If you have an 8-bit pixel that has a red value of 200 (bright red) and a Color Gain tool is used to
double the brightness of the red channel, the result is 200 x 2, or 400. However, 8-bit color
values are limited to a range of 0 through 255. So the pixel‘s value is clipped to 255, or pure
red. If now the brightness is halved, the result is half of 255, or 127 (rounded), instead of the
original value of 200.
When processing floating-point colors, pixel values brighter than white or darker than black are
maintained. There is no value clipping. The pixel is still shown in the viewer as pure red, but if
float processing is used instead of 8-bit, the second operation where the gain was halved
would have restored the pixel to its original value of 200.
Using Float with 8-Bit HD Video
There is also some value to using float color depths with an 8-bit HD video when the images
require a lot of color correction. Using float helps maintain precision by avoiding the rounding
errors common to 8-bit processing, as described above.
Detecting Extended Highlight and Shadow Values
Although floating-point processing preserves extended values below 0.0 and greater than 1.0,
also called “out-of-range values,” the viewer still displays them as black or white. This can make
it difficult for you to determine the overall dynamic range of an image.
To discover whether there are out-of-range values in a viewed image:
Right-click in the viewer and choose Options > Show Full Color Range.
Use the Show Full Color Range pop-up menu to detect out-of-range images.
Enabling this display mode rescales the color values in the image so that the brightest
color in the image is remapped to a value of 1.0 (white), and the darkest is remapped to
0.0 (black).
1365Chapter – 67 Controlling Image Processing and Resolution