Movies are shot at 24 full frames per second, or fps/p. Which is akin to a 24Hz refresh rate. However, televisions today with 4K resolution have a refresh rate of at least 30Hz.
This results in juddering when you play a movie on your 4K TV.
Juddering happens because the display device has a faster refresh rate than the frames of a movie being played. You will notice the image looks like the transition of scenes seems glitchy.
If you play a 24p movie on a 30Hz TV, that would result in 6 missing frames. The missing frames are what’s causing the judder.
However, 24p videos play smoother on a 120Hz TV because the 120Hz TV multiplies the frames five times. This means the frames and the refresh rates match — no juddering experience.
By that explanation alone, one can assume that you would have a horrible time watching a movie on a 4K TV with a 30Hz refresh rate. But that is not the case. You would only notice the juddering if the video is played in very slow motion.
The great news is, TVs released today have a feature that allows the TV to match the movie’s 24p playback.
Check out the video below to see the difference between a video with juddering and without juddering. The left side of the video shows 24p playback with juddering, and the right side shows the feature turned on that prevents juddering.
Aside from the TV feature that matches the movie frames and the TV’s refresh rate, the film industry also uses the 3:2 pulldown method during post-production or when they transfer the film to video format. They convert 24 fps to 29.97 fps.
The telecine, a machine that converts film to video, adds half a frame to each second of a video frame. This extends the frame of the video, essentially removing the gaps so that it can be smoothly played at 30Hz.
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Is 30Hz Enough for 4K Movies?
All 4K or high definition movies are rendered at 60 fps. This means it needs a TV with a refresh rate of 60Hz or higher for you to fully experience the high-definition video.
If you watch a 4K movie on a 30Hz TV, you will see it at 30 fps, not 60 fps.
The high-definition quality will be lost. But that doesn’t mean you can’t watch a 4K movie on a 30Hz TV. You can, just don’t expect you’ll get the same quality as if you watched it on a TV with a 60Hz refresh rate.
So, is a 4K TV with a 30Hz refresh rate bad? Not entirely.
If a 4K TV with a refresh rate of 30Hz is what fits your budget, then go for it. You will still be able to watch 4K movies and TV shows on it, just don’t expect the visuals to be as smooth as those found on TVs with higher refresh rates.
Which is Better: 4K 30Hz or 4K 60Hz?
If you’re going to buy a new TV, one with 4K resolution and a 60Hz refresh rate will be a better choice over one with only a 30Hz refresh rate.
The 60Hz TV will be able to play ultra-high-definition movies in all of its glory, so you can enjoy how the moviemaker made it.
Also, aside from playing UHD movies, most video games on PC and game consoles require at least 60Hz. So getting a TV with this refresh rate can also work in your favor if you enjoy playing video games.
TVs That Can Play 24p Without Judder
IN A HURRY? HERE IS OUR TOP PICK
Last update on 2023-05-31 / Affiliate links / Images from Amazon Product Advertising API.
Based on tests on whether 4K TV can play 24p movies without juddering, here are the top TVs that passed the test:
Hisense U9DG
- Dual-Cell Technology: Be first to own the first Dual-Cell Technology TV in the US. Two panels...
- 2,000,000 plus Dimming Zones: Two million zones, all managing brightness independently. Giving the...
- Quantum Dot Color: See over one billion shades. Quantum Dot produces purer, richer, more brilliant...
Last update on 2023-05-31 / Affiliate links / Images from Amazon Product Advertising API.
The Hisense U9DG is a 4K TV that uses Dual-Cell Technology wherein two panels are stacked together to deliver better contrast compared to regular LED TVs. It has a refresh rate of 120Hz with Ultra Motion technology that erases digital “noise” on videos for smoother video quality.
Samsung Neo QLED QN85A
- DETAILS IN THE DARK: See brilliantly intense, 4K UHD contrast delivered by Mini LEDs and Quantum...
- 4K UPSCALING: No matter what you watch, Neo Quantum Processor 4K transforms it to 4K through...
- RICH COLOR AND CONTRAST: Kick up the picture on your Smart TV with the vivid color and exceptional...
Last update on 2023-05-31 / Affiliate links / Images from Amazon Product Advertising API.
The Neo QLED QN85A from Samsung has a 4K UHD resolution made possible by Quantum Matrix Technology and Mini LEDs. It has a refresh rate of 120Hz, coupled with the Motion Xcelerator Turbo+ technology to deliver clear, smooth videos.
It is equipped with a Neo Quantum Processor 4K that can transform any video into 4K quality. It also comes with a built-in Alexa, Google Assistant, and Bixby, which can all be activated via voice command or connected devices.
LG NanoCell 65NANO90UPA
- REAL 4K NANOCELL DISPLAY: Bring your favorite shows to life with a billion rich colors. Get deep...
- A7 GEN 4 AI PROCESSOR 4K: Catch every detail with the smooth, crisp picture brought to you by our a7...
- HOME CINEMA EXPERIENCE: Get breathtaking picture and audio that makes you feel like you're in the...
Last update on 2023-05-31 / Affiliate links / Images from Amazon Product Advertising API.
The NanoCell 65NANO90UPA from LG features a 4K resolution with a refresh rate of 120Hz. It is FreeSync Premium compatible, which means no screen tearing when playing video games.
It comes with the “α7 Gen4 AI Processor” 4K that automatically adjusts the sound, and picture quality to ensure optimal viewing pleasure. This 4K LG TV has built-in Google Assistant and Alexa, allowing you to control the TV with just your voice or other connected devices.
Sony X85J
- 4K HDR PROCESSOR X1 – Powerful TV processing that delivers a picture that is smooth and clear,...
- MOTIONFLOW XR WITH NATIVE 120HZ REFRESH RATE– On-screen motion stays smooth and clear, allowing...
- TRILUMINOS PRO – Reproduces more colors than a conventional TV resulting in picture quality that...
Last update on 2023-05-31 / Affiliate links / Images from Amazon Product Advertising API.
The Sony X85J boasts a 4K resolution. It features MotionFlow XR technology with a 120Hz refresh rate to deliver smooth and clear video viewing even during fast-paced action-packed scenes.
It is equipped with the 4K HDR processor “X1” that helps with high-definition image processing, improved color contrast, and better frame transitions. It also uses the 4K X-Reality Pro feature to turn high-definition content into ultra-high-definition quality.
It does not come with a built-in Alexa, but it can be connected to Alexa or an Alexa-powered device so that you can use your voice to control it.
Amazon Fire TV Omni
- Cinematic 4K entertainment - Get true-to-life picture quality and rich, brilliant colors with...
- HDR like you've never seen - Dolby Vision brings spectacular color, contrast, clarity, and...
- Hands-free TV with Alexa - With built-in microphones, just ask to turn on the TV, and find, launch,...
Last update on 2023-05-31 / Affiliate links / Images from Amazon Product Advertising API.
The Amazon Fire TV Omni features 4K UHD resolution with a 60Hz refresh rate. It comes with a built-in Alexa, so you can use your voice to change channels or launch apps. You can also use the remote that comes with it or other Alexa devices to control the TV.
Conclusion
You can watch movies, high-definition or not, on a 4K TV with a 30Hz refresh rate. However, if you’re watching 4K movies, which use 60 fps, do not expect to see the movie in its ultra-high-definition format.
4K TVs today have refresh rates of at least 60Hz, which means they can fully support UHD movies and TV shows, and you won’t have to worry about juddering.
Vance is a dad, former software engineer, and tech lover. Knowing how a computer works becomes handy when he builds Pointer Clicker. His quest is to make tech more accessible for non-techie users. When not working with his team, you can find him caring for his son and gaming.