Hi,
To adjust the brightness on your TV, please follow the below:
Go to: Settings > All Settings > General & Privacy > Power and Energy Saving, then turn off Brightness Optimization, Energy Saving Solution, Motion Lighting, and/or Contrast Enhancer.
You can also adjust the Picture Mode to better suit your environment: Settings > All Settings > Picture > Picture Mode
• Standard – Default mode for general viewing
• Dynamic – Brighter and clearer, ideal for well-lit rooms
• Movie – Best for dark room viewing
• Eco – Energy-saving mode
• Filmmaker Mode – Preserves content as intended by creators
To fine-tune brightness, go to: Home > left directional key > Settings > All Settings > Picture > Expert Settings, then adjust the Brightness level (0–50) to your preference.
Lastly, please make sure your TV is running the latest firmware: Home > Home > left directional key > Settings > Support > Software Update > Update Now.
I hope this helps!
~Samsung Advisor