KONA Capture, Display, Convert v15.2 71 www.aja.com
Visually, in 8-bit video compared to 10-bit video, you will notice a substantial
difference. In 8-bit video there will be “contour lines” or “striations” visible,
particularly noticeable in scenes having soft gradients like a ramp or sunset. For
example, if a sky region is mostly the same color but varies by only a few digital
numbers from one side of the picture to another, you may see contour lines
where the signal passes from one digital value to the next higher value.
Since each numerical value in a 10-bit system is only one fourth as large as an
8-bit system’s, these contours become invisible and the sky varies smoothly.
10-bit video is often used when the source and output video (or “master”) is also
10-bit. Even if the input and/or output video is 8-bit, a 10-bit “project” will still
maintain a higher quality when there is a significant amount of effects rendering
involved.
About 12-bit Video
With the emergence of High Dynamic Range and Wide Color Gamut video,
support for even more colors became necessary. 12-bit video theoretically has
4x color resolution of 10-bit video, but current video monitor technology cannot
display this full resolution. However, 12-bit video can be useful for postproduction
and color grading purposes, as it allows greater control of subtle colors.
About RGB and YPbPr Video
RGB Video
Although RGB is used less in today’s video systems, KONA supports it for A/V
Monitor output. However, because the KONA (and SMPTE SDI’s) native format is
YPbPr, AJA recommends using YPbPr when the monitor supports it. The YPbPr
format provides headroom for “superwhite” and "superblack”, and these video
levels will be clipped when transcoding to RGB. Also, the RGB/YPbPr transcoding
involves a level translation that results in mathematical round-off error. RGB can
be configured in the Playout setup panel of the specific application you are using
with KONA.
YPbPr Video
KONA supports three different types of YPbPr:
• SMPTE/EBU N10
• Betacam (NTSC)
• Betacam (NTSC-J [Japan])
These three formats differ in level only and can be configured in the Playout
setup panel of the specific application you are using with KONA.
