Try adjusting your TV's Picture menu options to the 'Movie' or 'Filmmaker' setting & see if that improves it for you - also turn OFF the 'Picture Clarity' (also known as 'Auto Motion Plus' / 'Motion Smoothing' / 'Sports' / 'Soap Opera') setting.
You can also try different settings for the 'HDMI Black Level' & 'Dynamic Contrast' options as well.
Samsung Care is here to help you with 4K Suhd Tvs. Get started, find helpful content and resources, and do more with your Samsung product.
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Other links:
Unlock the best picture quality on your Samsung 4K UHD TV with expert tips for adjusting settings to match movies, games, and more.
www.lifewire.com
Whether you're a cinephile or hardcore gamer, you want the best video quality from your Samsung TV. Here's how to optimize settings for any use of your TV.
www.slashgear.com