One of the upshots of the ongoing unlimited wars is that all four of the major carriers now offer unlimited streaming of high definition (HD) videos.
HD video refers to 1080p resolution, sometimes called "Full HD", and a significant step up from 480p, generally referred to as standard definition (SD), or "DVD quality."
For many of us, 480p, 780p, 1080p etc. are just numbers. We know the higher ones equate to better videos, but that's about it. I used to be in this camp, until I did a little research. Now I can present to you The Idiot's Guide to SD vs. HD.
What the heck do those numbers mean?
The 1080 in 1080p refers to the number of pixels comprising the video's resolution. Pixels are the little dots that make up an image, displaying it's color. Resolution is the total number of pixels in a video or image.
The more pixels, the better the resolution. The better the resolution, the more detailed the video. The more detailed the video, the sharper the overall video image quality to our eyes, to a certain point (more on that later).
1080, 780, and 480 and so on denotes vertical resolution. Really, 1080 is 1920 x 1080, where 1920 part of that equation refers to the horizontal pixel count. Here are the common resolutions out there:
- 352 x 240 (240p)
- 480 x 360 (360p)
- 858 x 480 (480p)
- 1280 x 720 (720p)
- 1920 x 1080 (1080p)
- 3860 x 2160 (2160p, or 4K)
Standard definition starts at 240p and ends at 480p; 720p is semi-HD; 1080p is full-strength HD; everything above this is considered Ultra-HD.
Check out the clip below to get a sense of the difference in quality. It starts in 1080p and decreases in resolution over the course of the video; you can skip ahead to 480p at 1:47 (disclaimer: your ability to detect the difference will depend on the type of display you're viewing it on; also, make sure you have 1080p selected under settings in YouTube).
Are the differences between SD and HD videos perceptible on a smartphone screen?
This is the subject of much debate. One camp (including the late Steve Jobs) believes that the higher pixel density of HD and Ultra HD is wasted on small screens. Other pundits have gleefully hailed the advent of 1080p--and, more recently, 4K--in smartphone displays and videos. Research on the topic is inconclusive, and in the end you start to wonder how much it comes down to each person's vision. The jury's out on this one.
How much data does HD streaming use compared to SD streaming?
The data calculators don't agree on this, and really the amount of data can depend on the site you're streaming from, and the network you're on. According to Netflix, though, one hour of SD streaming will use .7GB of data, as opposed to 3GB for HD. That's not an insignificant difference, and why some carriers, like AT&T, give you the option of streaming in SD, and not counting it against your monthly data limits/de-prioritization thresholds. The four major carriers start de-prioritizing data to 3G or 2G speeds after the following limits have been reached:
Let's say you're on T-Mobile. A mere 10 hours of HD streaming would have you hitting 30GB, compared to about 43 hours of SD viewing. That's like 20 feature length films. Or one Ken Burns documentary.
What kind of toll does HD streaming have on battery life?
Any kind of video streaming takes a chunk out of your phone's battery, since the screen must be on continuously and an active internet connection must be maintained. Streaming in higher definitions puts further strain on your device's processors as they decode the video, further draining battery life. Every device is different, and so it goes with the exact amount of drain; it's estimated, though, that streaming an HD movie can cut your battery life by more than 50 percent.
What's the deal with 4K?
4K is labeled as such because it contains nearly 4,000 horizontal pixels. In fact, over eight million total pixels comprise 4K videos (and the screens they're watched on), which is four times as many as 1080p. That is to say, it's crazy detailed.
Whether the human eye can actually detect the difference between 4K video and the lesser 1080p — especially on a smartphone — is unclear (pun intended). CNET doesn't think so.
Whatever the case, 4G screens may become the norm in flagship smartphones in the not-so-distant future. Sony debuted the first 4K smartphone display in 2015 with their Xperia X5 Premium, and will soon follow that up with the XZ Premium.
Even if there isn't agreement on 4K's utility when it comes to regular smartphone use, everybody seems to be excited about its implications for virtual reality. This is because VR goggles like Google Cardboard place the screen very close to your eyes, such that the extra detail may very well make a difference.
Putting a bow on it
Now that you have basics of video definition, it's time to think about plans. If you decide that streaming in HD is important to you, you'll need to find a plan that either has a big data allotment or allows for unlimited HD streaming. Check out hundreds of plans via WhistleOut's comparison tool.