Recent Samsung TVs have a feature called "Auto Motion Plus," which is a form of motion smoothing. The motion smoothing is very bad because it makes the picture of a TV too smooth and sometimes a little strange.
What is "Auto Motion Plus"?
Auto Motion Plus works by increasing the number of frames per second you watch. In the United States, most TVs are filmed at 24 or 30 frames per second (fps), but almost all TVs are refreshed at 60 or 120 frames per second. So, the idea behind motion smoothing is that by inserting additional interpolated images, your TV can bring the content down to 30 frames per second at the reduced frame rate of smoothing high-speed refresh displays.
The problem is that people have become so accustomed over the years to watching certain types of media (like movies and TV shows) at 24 or 30 fps that it's strange to watch them at a rate of higher shot. Movies no longer look like movies. The high refresh rates seem a lot more "real" and can get you out of the immersion of a movie. For things like sports and games, it's good, but it can have strange effects on other content. Plus, the extra frames are often pretty fuzzy or just plain wrong.
How to turn it off
The option to disable it should be under the picture options of most Samsung TVs, and possibly in "Expert Settings". Look for an "Auto Motion Plus" setting.
This will open a drop-down menu with the options "Auto", "Disabled" and "Custom". You can disable it completely with "Off" or adjust its settings under the "Custom" option.
If you can not find the setting, it may be in a different menu, so it's best to check your TV manual. you can find online.