By using this site, you agree to our Privacy Policy and our Terms of Use. Close

it's called ACE contrast enhancement on that tv or advanced contrast enhancement.
I don't see any option to turn it off either in the manual. Did you turn light sensor off? That also changes the brightness. Light from the tv reflecting back on the tv can cause it to go darker.
You can try to turn off all the advanced settings anyway, not needed for blu-ray.