Web videos have one super feature that will ensure the death of all forms of traditional broadcasting. Don’t you want to know what that is? I’ll tell you.
The most powerful feature of web videos is: You can share them. You can pass them around like a bowl of popcorn, except this one never runs out. And you’re never charged for it!
I’m sure you have heard of this example:
Is there any other channel or program that can claim the numbers Youtube gets per hour? The only content I feel might rival Youtube is a FIFA World Cup Final, but even that is watched across many different channels, even though the feed might be the same.
On Youtube, everyone watches the same thing.
Are you making corporate videos or music videos? Are you making an indie feature or short? Are you producing a documentary or live event? In today’s world, your best bet is the internet. The chances of a video succeeding on the web are much higher than any traditional broadcast system. You no longer have to think about the web as your last option. Tomorrow, it will be your first.
Get it? It is almost criminal of any video content producer to overlook the web video business. Enough said. Now let’s move on in our quest to find the best video camera for web videos.
If your goal is to make videos for cinema or broadcast, and the internet is just an afterthought, this article is not for you. This article will show you what it takes to make a great web video, if the primary destination for it is the web, and only the web.
After we understand what a great web video is, we’ll see which video camera and gear does this for the cheapest price. Ready?
What makes a great web video?
I’m going to consider the following properties (for camera and video) as most important, technically speaking:
- Dynamic Range
- Frame Rate
- Data rate
Resolution is not one thing, it’s four:
- The distance between the display device and your eyes
- Visual Acuity of your eye
- Resolution of the device you are watching it on
- Resolution of the web video
There are other cool factors, too, which you can read about in Driving Miss Digital. But at this point, let’s keep it simple. This isn’t particle physics 101. If you’d like a quick primer on what resolution is, check out Pixels, Megapixels and Resolution.
The distance between the display and your eyes
From the Resolution of the Human Eye, you know that the minimum focus distance is 4 inches for the average adult (that includes teenagers too).
However, very few people read or watch anything at that distance. Usually, the comfortable reading or watching distance is at one foot, or 12 inches. This is the minimum practical distance we need to account for.
In a typical living room environment, one is unlikely to watch TV beyond an average distance of 25 to 30 feet. Usually, the ‘couch’ distance is between 6 to 15 feet.
Mobile devices will be held closer like magazines, while HDTV displays will be viewed from further away.
This chapter from the Comprehensive Rigging Guide tells you that watching a typical display takes this form:
It’s not good to get too close or too far. The sweet spot is your viewing distance. But –
We’ve just learned that it varies from one to thirty feet. Is there a way out? Of course there is.
Resolution of your eye
For the sake of simplicity, I’m going to measure visual acuity in ppi, or pixels per inch.
I’ve shown you how to calculate the resolution of the average human eye at these distances. Here are the results:
- One feet – 300 ppi
- Two and a half feet (Computer monitor) – 115 ppi
- 6 feet – 50 ppi
- 30 feet – 10 ppi
The message is clear. To make a great web video that will work on all devices, it should have a minimum resolution that corresponds to 300 ppi, practically.
Mind you, the acuity of the human eye varies from person to person, and from time to time. 300 ppi @ 1 feet will give you a video ‘without excuses’.
Resolution of the device you are watching it on
For simplicity’s sake, I’m going to assume a standard aspect ratio of 16:9, corresponding to HDTV. If you’re unsure what this is, check out Aspect Ration and Pixel Aspect Ratio.
The smallest device on which you are likely to watch a video is a smart phone, at a distance of one foot. If a smartphone has a diagonal screen size of 3 inches, at 300 ppi, you’ll need a phone with a resolution of 960 x 540.
Some phones that better this limit are:
- Apple iPhone 5 – 1136×640 @ 326 ppi
- Samsung Galaxy S3 – 1280×720 @ 306 ppi
- Nokia Lumia 920 – 1280×720 @ 267 ppi
Very interesting! Except for large monitors for PC displays or HDTVs, none of the other devices seem to have 1080p resolutions (except the Retina models but they’re easily overkill)! Does it mean we don’t need 1920×1080? Hardly.
At 6 feet, 1280×720 on a 24″ monitor will meet the 50 ppi limit at that distance, while the same resolution on a 42″ TV will only give 29 ppi, which is unacceptable. So, there are scenarios where 1080p is mandatory.
We have our answer:
Resolution of the web video
For a universal web video for all devices, you need a minimum resolution of 1920×1080.
Does 1280 x 720 work? Sometimes. Forget Standard Definition (PAL and NTSC).
Important: This resolution must be the practical resolution, not the theoretical one. Some cameras claim this resolution but in reality they don’t deliver. You’ll see why this is important shortly.
Color in video can be broken up into four parts:
- Color Bit Depth
- Chroma Sub-sampling
- Color Space
- Color Gamut
Color Bit Depth
From Color, Color Bit Depth and Color Models, you know that 8-bit video can hold more colors than the eye can see. Ultimately, if you were to shoot in, say, 10-bit, you’d still lose out on many colors by converting it back to 8-bit – which you have to do for web video.
8-bit is good enough for the web.
Ideally, you DON’T want to sub-sample the color information. This is akin to licking the icing off a cream biscuit before offering it to somebody. If it were up to me, I’d ban it outright.
But it’s there for one important purpose, which I must admit, is an extremely valid one. The file size of a video sampled at 4:2:0 is roughly half that of a full RGB (4:4:4) video. 4:2:2 is approximately 67% the size of RGB or 4:4:4. To know more about sampling, start reading Sampling Analog Signals.
Understand this: The average consumer will not notice the difference between 4:2:0 and 4:2:2. In fact, most professionals can’t see the difference either. Unfortunately, cameras don’t allow us the opportunity to test both of them while keeping everything else constant.
The only way I know of testing them side by side is converting a 4:2:2 still image, uncompressed (so the codec won’t interfere) to 4:2:0. But, which software allows this? Welcome to sampling voodoo 101.
Long story short, you obviously want an image that has not been sampled, failing which, you work your way down to what you can afford. If all you can afford is 4:2:0, it’s perfectly all right for the web.
How do I know this? Other than experience, you might want to look into the fine print every uploader puts under his or her video: “Unfortunately you can’t see the brilliant mind-blowing quality of so-and-so camera on this compressed web video…”.
I rest my case. If I can’t see it, why do I need it? Stop worrying about it.
I’ll keep this one short. For better or for worse, the color space of most devices is going to be either sRGB or Rec. 709; both of which are practically similar enough that nobody will ever see the difference with their eyes.
How can I say that confidently? Simple, color spaces are theoretical things, as I’ve explained here. You can see the difference in the numbers, but you won’t see it in the colors.
Bottom line, if you shoot in HDTV Rec. 709 (ITU-R Recommendation BT.709), then you are good for every display out there. Luckily for us, every camera shoots Rec. 709.
This is where the men are separated from the boys. Just because two devices share the same color space does not mean they will show the same color. Two broadcast monitors designed for 100% Rec. 709, say, will show identical images for all practical purposes. But two consumer grade monitors or tablets or phones might not.
That’s because each display device (cameras, too!) has a gamut – the practical colors that it can show or see. There’s nothing you can do about this at the display or delivery end. All you can do is ensure you are watching and grading your footage on a monitor that can show 100% Rec. 709.
And don’t worry if you can’t afford a broadcast monitor. This is one instance where most consumer devices lag behind cameras. You can miss a few colors here and there – you won’t know it because you didn’t see it while shooting or grading, and your consumer will never know about what wasn’t there.
If it looks okay to everyone who matters, it’s okay – nevermind what the monitor or waveform says. I’ve already explained my feelings about this here.
So, here are our color specs: 8-bit, Rec. 709, sampled at 4:2:0 or better. Now we’re getting somewhere.
In the next part we’ll cover the rest of our properties, after which I will unveil the best video camera for web videos!
Next: Part Two