User Manual

Table Of Contents
Together, all of this trimming metadata guideshow the CMU (software or hardware) transforms
the image from the Mastering Display specified in the Project Settings to the Target Display
specified in the Dolby Vision palette. This is possible because the CMU is actually the
functional equivalent of the Dolby Vision chip that’s inside each Dolby Vision-enabled
television; what you’re really doing is using the CMU to makeyour SDR display simulatea 100
nit Dolby Vision television.
The Secondary Trims controls as seen on a licensed Dolby Vision system
Previewing and Trimming At Different Levels
Additionally, the software (or hardware) CMU can be used to output 600 nit, 1000 nit, and 2000
nit versions of your program, with different gamuts, if you want to see how your master will scale
to those combinations of peak luminance levels and standards. This, of course, requires your
DaVinci Resolve workstation or hardware CMU to be connected to a display that’s capable of
being set to those peak luminance output levels.
Though not required, you also have the option to set the “Trim Controls For” drop-down menu
to different combinations of peak luminance, gamut, and color temperature, in order to visually
trim the grades of your program at up to four different peak luminance levels, including 100 nit,
600 nit, 1000 nit, and 2000 nit reference points. Choosing a setting from the “Trim Controls
For” drop-down menu sets you up to adjust trim metadata for that setting.
Choosing different settings from the “Trim Controls For” drop-down menu lets you can optimize
a program’s visuals for the peak luminance and color volume performance of many different
televisions with a much finer degree of control. If you take this extra step of doing a complete
trim pass of your program at multiple nit levels (using the Dolby Vision controls), then Dolby
Vision-compatible televisions will use all of the artistic trim (Level 2) metadata you generate in
each trim pass to ensure the creative intent is preserved as closely as possible across a wide
variety of displays, in an attempt to provide the viewer with the best possible representation of
the director’s intent, no matter where it appears.
For example, if a program were graded relative to a 4000 nit display, along with a single 100 nit
Rec. 709 trim pass, then a Dolby Vision-compatible television with 750 nit peak output will
reference the 100 nit trim pass artistic guidance metadata in order to come up with the best way
of “splitting the difference” to output the signal correctly. On the other hand, were the colorist to
do three trim passes, the first at 100 nits, a second at 600 nits, and a third at 1000 nits, then a
750 nit-capable Dolby Vision television would be able to use the 600 and 1000 nit artistic intent
metadata to output more accurately scaled HDR-strength highlights, relative to the colorist’s
adjustments, that take better advantage of the 750 nit output of that television.
Chapter – 8 HDR Setup andGrading 248