Understanding Video Resolutions

Today's iPhones can record up to 4K video resolution and the new Apple TV can play back 4K movies. What is the difference between 4K and 1080 HD? How about older standards like 720 HD and SD video? Learn the difference and how it can affect video quality. Learn how to set your video recording resolution on your iPhone.

You can also watch this video at YouTube (but with ads).

Video Transcript: So let's take a look at video resolutions. There's been a lot of talk about video resolutions because the new iPhones can record up to 4K video. And the new Apple TV can play back 4K video. What is 4K video and how is it different than what we had before? So let's look at four main video resolutions that we've dealt with over the years. 
These are representations of those four. At the upper left we see the standard definition video. Standard definition video can be defined a lot of different ways but one way to look at as 640 X 480 pixels totaling 307,000 pixels. This is the resolution that you got on standard TV say in the '70s and '80s, although they weren't digital so the pixels were kind of blurry. It was adopted by DVD's  so DVD's used standard resolution although not always 640X480. Sometimes they're widescreen so they're wider than 640 pixels across but still 480 pixels high. So that's standard resolution. That's where we started and that's where computers handled video in the '90s. 
Then we moved on to high definition. But there were several versions of that. The first was called 720. 720 improved everything considerably. It standardized everything at 1280 X 720 pixels which is three times as many pixels in the image as standard definition video. A lot of phones, a lot of cameras, and everything used 720 and then it became standard on TVs that you bought at the store. 720 high definition video. 
Things got even better than that and we got to 1080. 
1080 is 1920 X 1080 pixels. So you can see that the number used here, 720 or 1080, is the vertical dimension. So 1920 X 1080 turns out to be 2.1 million pixels. So significantly better than 720. Now you can see here in these representations I'm showing everything as if every pixel is the same size. So if you were to have a TV where a pixel was a certain size you're TV would have gone from the small image at the upper left to the larger image at the bottom. 
Now we're in the era of 4K. 4K is 3840 pixels wide and 2160 pixels high. 8.3 million pixels. Four times the resolution of 1080. Believe it or not the new iPhones can record at this and TVs that you get at the store, the nicer ones, can play this back including Apple TV which plays this back on lots of different movies, rentals and particularly some of the new releases. 
So you can see how things have significantly improved. But you really don't see much of a difference here. You just see that if you were to display things as every pixel being the same size you could have a much bigger picture. Let's take a look at what happens if we zoom in on a portion of this image here and we show you the same portion of the image but at each resolution.
So first let's start 640 X 480, standard resolution. This is what the middle of the image looks like. You can see we've zoomed in a lot. So you just see these blocky pixels. There's the monument, the bus, and the street. It looks like an '80s video game. Now if we looked at the same portion of the image at 720 we can see things improve a lot. We can still see blocky pixels. I mean we are zoomed in at the very center of the image. But there's a much higher resolution. 
Now we go to 1080 and  we can see something much more significant. You can see people kind of start to take shape. You can still see the pixels really clearly here zoomed in at this resolution but there's much better definition. Let's review. Go back. There's 640. There's 720. There is 1080. Now let's go and look at 4K resolution. You can see it's a much bigger improvement over the original 640 x 480 resolution. You can see how things have improved over time in not only our video playback devices but also just our cameras in our iPhones. 
So the ways this may effect us in our everyday life is say if you still make DVD's  but you maybe take the nice 1080 or 4K video from your iPhone and then make a DVD out of it the resolution that you're going to get is the one at the upper left, standard definition. So you're looking at it in pretty high definition on your Mac screen and then you make this DVD and you go to watch it on your TV and you see it doesn't look as good. That's because it's in standard definition.  Even if you say have a television that's doing 720 and you look at video on your Mac and then you go look at it on your TV streamed to it. You see it's not that great resolution. Just keep in mind your Mac screen could very easily be something between 1080 and 4K. If your TV is 720, of course the video is not going to look nearly as crisp and have as much detail as it does on your Mac's display.
So some things to think about when you're watching video. When you're shooting video you should probably shoot at the highest resolution you can because while you may have a 720 TV today or you may be producing DVD's today think five, ten years from now when you're watching this footage again. If it's important to you, you may easily have a 4K TV or playback device and be disappointed if you only saved the video and recorded the video at 720. So be thinking ahead to the future when recording your video as well. 
Now on your iPhone, in the Settings app, go to the Camera settings and there's a record video option there. You can set the recording resolution. So here on my iPhone X I can go 720, 1080, and 4K. I can change the numbers of frames per second. So standard is 30 fps. That's what you're used to seeing but the iPhone X is capable of recording 4K all the up to 60 fps. Which means that do things like slowing down the video, doing slowmo, or grabbing still frames at a much higher resolution. However, of course, the higher you go the more space it's going to take up on your device. The more space it's going to take up on your hard drive as you archive it and put it in your photo library. So you want to think about that and balance them as you decide which one to use. But do pay attention to the setting and set it to what you want before you record any video.

Comments: 5 Responses to “Understanding Video Resolutions”

Kristie

7 years ago

This is an interesting article. I have an iPhone 5 and when I send a video to my daughter who has an iPhone 8, she says the quality is very poor. I wonder if this answers our question as to 'why'.

Gary Rosenzweig

Kristie: Depending on how you send it the video is probably compressed and shrunk even more, so the quality would be low. Uploading to a service like YouTube and sharing the link is a good way to send high quality video.

Richard Scotte

This really helps me to understand the process of video and the different qualities I have seen over the years. At 87 yrs I'm always playing catchup with the latest technology so please keep this articles coming. PS love the sub-titles. (thanks)

Mike Milton

Interesting vlog and surely helpful to its intended audience. It is accurate except that the discussion is really about UHD (2160x3840) and not 4K (2048x4096). Calling UHD 4K is a marketing thing that has resulted in 'real' 4K taking in the name C4K or cinema 4K. C4K also has a slightly different aspect ratio, appropriate for theatres.

My issue with the vlog is that, at typical viewing distances, HD and UHD are indistinguishable. See this http://yedlin.net/ResDemo/ResDemoPt1.html

Darrell

Thanks for this informative, easy to understand explanation. Very helpful!

Comments Closed.

Understanding Video Resolutions

Comments: 5 Responses to “Understanding Video Resolutions”

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