Understanding Video Resolutions

5th January 2017 | Posted in Resources

When working with a video production company, making a video yourself, or even just watching videos online, you may come across the concept of ‘Video Resolution’.

Considering the date (this post was published in January), you may be thinking that video resolutions are like New Years resolutions… But no, I’m not going to be asking you to start a diet you’ll never stick to or quit a habit you’ll still be doing in six months time. Instead this post is referring to something a little more concrete.

When I say video resolution, I’m talking about the size of your video. In most cases, videos come in one of several set sizes, some of which you may be familiar with already from that time you last bought a TV, games console or mobile phone. Here are the most commonly used ones.

Standard Definition, 720p HD, 1080p HD and 4K.

So what’s the difference and what are they used for?

Note: I will preface this post by saying that it has been written to provide broad understanding of this topic and a lot of concepts have been simplified. If you’re looking for something more technical you may want to look elsewhere.

Standard Definition

Let’s start with standard definition. Standard definition video was the de-facto resolution for video until it was surpassed by high definition for most uses in the mid-2000s. While most video content is no longer filmed in standard definition, you’ll still find SD video in use on DVDs and for a lot of broadcast TV.

While SD video comes in at the low resolution of only 640×480 pixels, SD video tends to require less storage and bandwidth which makes it better for situations where data is constrained. For example, when broadcasting live. Online, you may also see SD videos described as 480p.

HD

Up next we have HD. Any resolution larger than Standard Definition is considered High Definition and is assigned a number based on, essentially, how many pixels high the image is. (The history of these numbers is a bit more complex, but this is what it boils down to.) To keep this short we’re going to talk about 720p and 1080p HD.

720p HD is perhaps one of the most sensible HD formats for videos on the web at the moment. With a resolution of 1280×720 pixels it provides enough resolution for the video to be clear and crisp without requiring lots of bandwidth to stream. This is very helpful for users on mobile devices who have a data cap. It provides a good balance of quality and file size.

However, the HD resolution that most people will know is 1080p. 1080p HD takes HD to a resolution of 1920×1080 pixels. 1080p HD is the de-facto size for HD content these days with most TV show and films being distributed at this resolution on Blu-Ray discs. You’ll be hard pressed to find modern content that isn’t recorded at this resolution or a modern device that can’t play it. So what’s next?

4K

It’s no question that 4K is the future of video, named for having -in most cases- a resolution of 3840×2160 pixels. Yes, it’s not actually 4000 pixels, but it’s close enough that you can let them off.

In terms of resolution, 4K is double the size of HD, which means that any 4K images produced should be much higher quality that its lower resolution predecessor. You can fit four 1080p images into a single 4K image. That’s a lot of data!

At the time of writing 4K isn’t particularly common, but more and more devices are starting to support it. Some smartphones can now record video in 4K resolution (more on this in a minute) and 4K televisions are starting to lower to an affordable price.

The only downside is that the content needs to catch up; 4K isn’t being used commonly enough by content creators yet, with many of us opting to use more powerful 4K cameras for their better quality 1080p features, such as slow motion or the ability to digitally crop in to an image for reframing in post-production. (This is quite handy for drone footage where the propellers may accidentally creep into the top of the shot, for example.)

I expect that we’ll start to see a lot more 4K content over the next year or two but for now it’s little more than a buzzword to sell new gadgets.

Is “high resolution” the same as “high quality”?

Now for some mythbusting. I’m afraid that resolution is not the same thing as quality. Your new smartphone may have a 4K resolution camera but that doesn’t necessarily guarantee that the camera is very good. Think of a video’s resolution as being like a sheet of A4 paper. You can either draw on that paper with a fine art pencil or with a wax crayon. The smartphone’s version of 4K is more like the crayon, whereas the sort of cameras a professional video production company would use would more like be fine art pencils. Why is this?

I don’t want to get too technical here, but one of the biggest factors in video quality is the video’s bit rate, which determines how much data the video contains. A 1080p HD video with a bit rate of 100Mbps (Megabits per second) will look better than a 4K video with a bit rate of 15Mbps because the 1080p video has more data in its image, even though the 4K video has a higher resolution.

In an earlier draft of this post I tried to make an analogy with pancakes, saying how bit rate is like the amount of batter (data) you have, and resolution is how far you stretch the pancake out. You can have a large pancake without much batter that’s really big and thin (low quality), or you can have a smaller pancake that’s much thicker (better quality).

I’m not sure my analogy works too well, and the technical aspects of this stuff can get really detailed (far more than even I understand and I do this for a living), but it does give you a basic idea of why the size of the video shouldn’t be your main priority… But it doesn’t help that consumer devices will opt to include a high resolution but low quality 4K option to get that coveted ‘4K’ badge on their specification sheet and shout about it in their marketing. (Therefore making the average person think that higher resolution equals better product, which simply isn’t true.)

The only downside of having a higher bit rate video is that your video file will be larger. Larger file sizes mean that you’ll need a bigger hard drive to store your video, and it will take longer to move it to another drive or upload in the future.

So how does this effect you?

Being a little bit more savvy about about video resolutions can be really helpful as you embark on your next video project. When video resolutions are being used as marketing buzzwords for new gadgets, it’s easy to get swept up with the idea that you need the latest and greatest option when in reality the benefits are minimal.

In my experience there’s usually little need to deviate from the norm (which at present is 1080p HD), but sometimes there are good reasons for aiming higher  – or lower. For example, you may want to record your next video in 4K if you plan to show it on large screens at an exhibition. Equally, I’ve found that I’ll often deliver long event recordings and interviews in standard definition to reduce the overall file size, which helps our clients out when they need to store a copy of the video on their company’s computer system for future reference. Sometimes the additional resolution, even of a 1080p HD video, is doing little more than using up space on a computer hard drive that could be given to something else instead.

So, with that in mind, let’s make it our New Year’s resolution to be smarter about video resolutions.

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