Tut_ForceFullDR

Fixing HDMI Dynamic Range (Black Levels)

In case You find that the black levels on the HDMI monitor doesn't go as black as the monitor should be able to. You can try this fix that has worked for me:

Why and how to fix

By default, the Raspberry Pi often outputs a "Limited" color range (16-235) over HDMI, which lifts black levels and makes them look milky. We fix this by running a script via systemd on boot to force "Full" RGB (0-255).

Part 1 - Make the script executable

Navigate to the VOP folder and grant execution rights to the utility script in its specific tools folder:

cd ~/VOP
chmod +x CaliTools/FullRGBFix/force_full_rgb.sh

Part 2 - Create the systemd service

Create a new service file using the nano text editor:

sudo nano /etc/systemd/system/vop-rgb-fix.service

Part 3 - Add the service configuration

Paste the following text into the editor. (Note: Replace <YOUR_USERNAME> with your actual Pi username):

[Unit]
Description=Force Full RGB Range for VOP Monitor
After=multi-user.target

[Service]
Type=oneshot
ExecStart=/home/<YOUR_USERNAME>/VOP/CaliTools/FullRGBFix/force_full_rgb.sh
RemainAfterExit=yes

[Install]
WantedBy=multi-user.target

Save the file and exit nano (Ctrl+O, Enter, Ctrl+X).

Part 4 - Enable the service

Tell systemd to reload its configuration and enable your new service to run on every boot:

sudo systemctl daemon-reload
sudo systemctl enable vop-rgb-fix.service
sudo systemctl start vop-rgb-fix.service

Once this is enabled. Your deep blacks should be permanently restored on the monitor upon every startup.