Lumagen Radiance Pro 444 Series Owner's Manual page 35

Section 9 - Calibration
For both HDR and SDR calibration, setting the black level correctly is the first and most important step in
calibration. An incorrectly set black level will make the image look "washed out." Having the correct black
level will increase the image contrast ratio and provide an improved image. Setting the black level is
something that should be done at the time of installation for every installation, even if no other calibration is
planned. Adjusting the black level does not require any special equipment or training.
Video Black
To adjust the black level, select the "Reference Pattern" mode test pattern (see Tech Tip 5 for
information on test patterns) from the "Other" menu. Then increase the display's Brightness (black) control
until the black-field area becomes visible. Then reduce the display's Brightness control until this black
background area does not get any darker with an additional click of the control.
Contrast 2
After adjusting the display's Brightness control, select the Radiance Pro's "Adjustable Pattern" .
Then the Radiance Pro MENU button to bring up the Radiance Black setting for the current CMS memory.
Then press OK to enable editing the black level. Look for the vertical bars in the middle of the screen. There
are nine of these, which are a black (0%) vertical bar in the very center of the image, four vertical bars
(1%, 2%, 3%, and 4%) just to the right of this center black bar, and four vertical bars (-1%, -2%, -3%, -
4%) just to the left of the center black bar. If necessary increase, or reduce, the Black level for the current
CMS memory until the +1% to +4% bars to the right of the center black bar are visible versus the center
black bar, and the -1% to -4% bars to the left of the center black bar are not visible versus the center black
bar. If the black levels are not good enough in the display, the -1% and +1% bars may either be both
visible or both not visible for various settings. In this case it is most important that the -1% bar is not visible
as compared to the center black bar. Once you have this adjusted, press OK to accept. Black level should
be adjusted for both CMS0 (SDR) and CMS1 (HDR).
Typically, the calibration software makes two sets of measurements, one in the display mode that will be
used for SDR/Rec709 material and one in the display mode that will be used for HDR/Rec2020 material.
Alternately it is possible to use a single bright mode with a large Gamut for both HDR and SDR sources. For
this you select the output Colorspace as SDR2020, SDRP3, or SDR709, depending on the native Gamut of
the projector or display, for both CMS0 and CMS1.
Once calibration has been completed enable the CMS1 → Colorspace → Colorspace = Auto Convert. For
CMS1 → HDR Mapping enable HDR Intensity Mapping and set the CMS HDR Display Max Light.
You should try several Display Max Light values using it as a coarse "brightness" control to see which
gives the best HDR image with default HDR Mapping parameters. With Dynamic Tone Mapping enabled,
pick a scene in a high "MaxCLL" HDR movie with both dark and bright areas (e.g. pickup truck explosion in
Mad Max Fury Road™ at 28:29) to adjust HDR Intensity Mapping parameters. Pause the scene and then
adjust the Max Light entry in the CMS1 → HDR Mapping menu.
For the first scene you adjust, it is recommended you choose a movie with a "MaxCLL" brightness of 3000
or higher (such as the above Mad Max Fury Road scene). Change Display Max Light (leave "Ratio" at 0),
as a coarse "brightness" setting. Later view a lower brightness movie with a MaxCLL around 1000. If
necessary, you can use the Ratio parameter in the input memory HDR Mapping menu to adjust for
differences between that scene and the brighter source used to set HDR Mapping Max Light.
For projectors with light output from about 16 to 30 foot-Lamberts Display Max Light settings roughly in
the range of 200 to 500 range are typical. The correct choice for your system is affected by the projector
light output, the screen "gain," and your personal preference concerning trading off normal scene detail
versus highlight detail.
NOTE:
There are several other HDR Tone Mapping controls, but for most systems only Display Max Light needs
to be adjusted since the default parameters work well. However, the other controls are available to tune the
image for specific screens or projector/TVs, or if you want to use the available intensity range more for mid-
tones, or for highlights. Use the HDR Mapping parameter input menu to adjust to your preference.
Copyright 2007-2017 Lumagen, Inc 32 Radiance Pro, Rev 071719