– Why do 4K videos look like they have more details than in the real life?

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Or they truly do.

In: Engineering

35 Answers

Anonymous 0 Comments

Maybe you need glasses? Real life is far clearer for me.

Anonymous 0 Comments

Either you’re watching a close up much closer than you would or could ever get in real life or you need glasses.

Anonymous 0 Comments

I haven’t seen this posted yet – it’s the refresh rate. It has nothing to do with the amount of pixels, it just happens that most 4k TV sets have a higher refresh rate than 48 hz.

The magic number is around 50-60 frames per second. Below that threshold, your eyes think they are looking at a still image, so your brain doesn’t update the image as often, which means it doesn’t notice all the details.

Above that rate, your eyes start to notice that the image is changing fast. Due to the physics of how your eyes work, the Cone structure in your retina waves back and forth at around 60 hz. Each cone has several sensors, or pixels, that detect light, and these pixels basically report when they see a change. Each wave is basically one scan, so each cone is sending signals to your brain at that rate. If the cone sees a difference on its next pass, it sends a signal. If not, nothing happens, the cone stays quiet and waits.

In a 24 fps movie, the frame has not changed by the time your eyes make a second “pass.” The cones don’t see any difference, it’s the exact same image and nothing has moved or changed. So, those details don’t get highlighted. Ironically this results in your brain ignoring the problems so you don’t notice the cheap set, or the makeup, or the fake clothes.

At a higher refresh rate, the cones see different things every “wave,” and this allows a higher resolution. More cones are being activated because of the higher refresh rate, and this allows your brain to pull more data out of the image. Now suddenly the cheap fabric looks gaudy and tacky.

You have thousands upon thousands of cones doing this all the time. Your brain (as well as your eyeball itself) are using Stochiometric Resonance to build the image. By taking multiple copies of a noisy signal and layering it atop itself, you can then remove the noise and you are left with the signal.

Your brain does that. It takes thousands of inputs, decides what to ignore and what’s real, then passes the completed, processed signal to the next part of your brain. It’s just a matter of chance and biology that some footage is below this threshold and some is not. Below the threshold, your brain fills in the details and shows you what it thinks it should be. Above that, your eyes catch enough detail that your brain handles it differently.

Source : an Ars Technica article I read a few years ago and haven’t been able to find since

Anonymous 0 Comments

Reminds me of thinking similar things in the 80s between normal weekly TV programs, and daily soaps. The daily soaps always looked clearer..but the evening shows looked…better.

Anonymous 0 Comments

Phone recorded videos are always over sharpened.
(sometimes your monitor or TV adds even more sharpening during a signal processing pass)

Tasteful sharpening is actually very hard and it`s a must for digital cameras. (what looks good in an Imax cinema is not going be the perfect amount and even method for smaller screens and even those just have too much variety, so they usually go with some interesting compromises)

Plus what everyone else is saying about up close faces, size, distance, magnification and focus.

Anonymous 0 Comments

For some reason the comments section made me think of this https://www.youtube.com/watch?v=V-fRuoMIfpw

Anonymous 0 Comments

With cameras every part of the image is in focus. With your eyes only a relatively small circle in the middle is focused (the rest is your peripherals). Also every camera has 20/20 vision, not true for all eyes. Your eyes also have blind spots and other obstructions.

You notice more detail because there is more detail.

Anonymous 0 Comments

Get glasses mate. It would literally change your life. I thought i had 20/20 vision until I did an eye test lol.

Anonymous 0 Comments

4k videos shine a light at you. Real life most things refract light. Now that in itself doesn’t mean screens are brighter than looking outside on the grass. And our eyes are very good at looking for dynamic ranges of light. But when you take pictures or videos in 4k, often you want to optimize for what the audience sees. And we get good at controlling the scene. And with each pixel being its own light source we can do things like hdr where shadows are highlighted and over saturated skies are toned down to show contrast.

Even if you don’t do hdr, cameras automatically adjust to give a range that is good for display.

Anonymous 0 Comments

In no way can a rendered or generated image be more detailed than real life. That doesn’t make sense.