Friday, November 13, 2020

Focusing a Streaming Webcam

One of the most highly sought-after pieces of equipment for a Twitch streamer is a good camera. We all want to look good on our streams, after all. As I've mentioned in previous entries however, it's not always necessary to upgrade your camera to make your facecam shots shine. In the entry How to Make Your Camera Look Better, I took you through the two most important aspects of a good looking camera shot: composition and lighting. By understanding those, your frames will look a lot more professional. But there's another, more technical feature, which streamers often struggle with. In this entry, I'll teach you to understand your camera's focus in order to create a much more stable image. 


Focus, as it pertains to a camera, is what causes some things in frame to be clear and some blurry. But how does focus work? Why is it that some cameras make the background super blurry and some don't? What causes certain cameras to switch what they're focusing on at seemingly random times? Learning what makes cameras and lenses tick is a massive rabbit hole, but it's not necessary to understand everything about them in order to create a nice looking Twitch stream. For our purposes, it's easiest to understand lenses when you think of them as eyes. This comparison might seem overly simplistic, but you'd be surprised how close to reality it actually is. It's so close in fact, that you can test out several camera focusing tricks simply by holding fingers up in front of your eyes in various positions. And throughout this entry, I'll ask you to do just that, so be ready to participate if it's safe for you to do so. 

Focus controls which parts of your frame are
blurry and which are clear.

The most popular kind of camera Twitch streamers tend to use is a webcam, either built into the computer itself or resting above the monitor. These webcams are designed for maximum ease of use, and therefore have many automatic settings enabled by default. One of these settings is auto-focus. This means the camera will decide for itself where the subject is placed in frame, and will focus its attention on that. This is very useful, because it offers you the freedom to move around your frame forwards or backwards, and not worry whether or not the camera is picking you up. You usually don't need to do anything fancy to make a stream look good with autofocus, but it's useful to understand what causes your camera to choose its subject. You'll often see streamers attempt to hold an object up to their camera for example, only for the lens to wildly alternate its focus between the close object and the streamer's face behind it. This is because the camera is still able to see two distinct planes- the face it was focusing on before, and the newly introduced close-up item- but it can't focus on both. To demonstrate this, try closing one eye and holding your finger about 6 inches from your other eye. If you focus on the finger, the wall or scenery behind it will be blurry. Now if you focus on the wall, the finger will be blurry. No matter how hard you try, you can't make both come into focus without moving the finger. It's the same with camera lenses. To get your camera's autofocus to easily zero in on the object you're holding close to the lens, try using your other hand or a piece of paper to block the background. This makes it so that the camera can't see anything except the closer object, and it will be forced to settle on what you want it to look at. You can try this with a finger as well. Close one eye and hold a finger six inches from the other eye again. Now take your other hand and press the palm behind that finger, so it acts as a background. Now, whether you're focusing on the finger or the palm, they're both in focus. That's because they're so close together that the eye doesn't need to choose anymore. There's no more foreground and background, it's all just foreground. 


Focus isn't all-powerful though. Every camera lens, from a webcam to Hollywood cinema glass, has its limits for how closely it can focus on an object. If you attempt to show something closer than that point, it will always be blurry, no matter how much focusing you do. You can test this with your finger too. Try closing one eye and placing your finger right in front of the open eye, so it's almost touching it. Now try to focus your eye on that finger. You can't do it. Unless you move the finger back, you won't be able to see it clearly at ultra-close range. The same holds true with cameras- each has a different limit, but they all have a point of no return like this. 

When using an autofocusing camera, you also want to make sure the shot itself is somewhat controlled. When you're sitting in your chair playing a game for example, there shouldn't be anything closer to the camera than you are. This depends on your setup, but if you have a corner of your lampshade, or a toy, or a book in the corner of the frame, sitting closer to the camera than your face, then the camera will likely be spending the whole show racking its focus between you and that foreground object. This is a problem you can easily identify by watching your streams after the fact. If you see something like this happening, check what the camera is focusing on other than your face and either relocate or remove it from the frame. 

Harsh backlights can mess with your camera's
focusing ability.

Sometimes, even if you've removed any extreme foreground objects from your frame, your camera will still have a hard time finding focus. This might be due to an imbalance of light, or just an overall lack of light. Cameras have a hard time seeing in the dark. The less light in your scene, the less visual information your camera will have to work with. You might not be able to tell by looking at your camera shot that it's too dark in your room, because most modern cameras will automatically turn on low-light compensation, making it look bright in frame even when it isn't bright in your camera's sensor. But that's just an effect- it doesn't mean the camera itself is able to see you any better. Try introducing more light into the area where you stream, and see if this solves the problem. This indecisive focus can also be caused by improper placement of lights- an ultra-bright light or window behind you in the camera shot will sometimes pull focus away from your face as well, so make sure your face is the largest and brightest thing in frame. To learn more about properly setting up lights, see the entry I mentioned earlier called How to Make Your Camera Look Better

Depending on how your stream is configured, focusing your camera can sometimes be a troublesome task. But by keeping these simple camera lens mechanics, as well as their limits, in mind, your stream will look much more stable. So now you just have to make sure you look good, because you won't be blurry anymore! 

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