What motion smoothing is doing to your picture
Motion smoothing, also called the soap opera effect, is your TV inserting extra frames between the real ones to make movement look smoother. It is useful for sports and games, but on movies and TV shows it makes everything look like a live studio broadcast — faces take on a hyper-real, video-like sheen. The effect is most obvious in slow pans and scenes with people walking. Most sets ship with smoothing set to a Standard or Auto level, so you may have been watching it for years without realizing.
Find the switch on your brand
Each brand buries it under a different name. On Sony sets, find 'Motionflow' in Picture settings and set it to Off, or choose 'Custom' with both sliders at zero; Sony's 'Cinema Pro' mode disables it too. On LG, open Picture > Picture Mode Settings and set 'TruMotion' to Off. On Samsung, it's 'Auto Motion Plus' under Picture > Clarity — slide it to Off, and skip 'LED Clear Motion' since it dims the panel. On TCL and Roku TVs, check Advanced Settings for 'Action Smoothing' or 'Judder Reduction.'
If your TV offers it, the fastest fix is Filmmaker Mode, a preset that switches off smoothing, sharpening, and similar processing in one step; it lives in the picture settings, sometimes on a dedicated remote button. Expect two side effects: some TVs dim slightly with smoothing off, and menus may grey out related motion options — that is normal. If you watch sports, turn smoothing back on only in the Sport picture mode and keep movies clean.
Do it once per input
Motion smoothing is remembered per picture mode and per input, so turning it off in 'Standard' mode does nothing for 'Cinema' or for your game console's HDMI port. Walk through every input you actually use — streaming box, cable, console — and repeat the steps. It is about two minutes per input, done once. If a show still looks like a soap opera after that, check the source: some sports and news channels broadcast at 60 frames per second natively, and no TV setting can remove motion baked into the feed.
When you are finished, play a movie you know well and let a slow scene run. The gentle judder you see at 24 frames per second is the movie looking like a movie again. Give it a week — your eyes adjust, and the soap opera effect stops being something you ever notice.