Understanding Depth of Field and How to Create a Professonal Film Look for Your Videos [Reel Rebel #7]
In today's Reel Rebel video production tip, Stephen Schweickart gives an overview of a depth of field, which is ultimately determines your focus area. Understanding and controlling the depth of field can be one of the most valuable tools to create more interesting, creative, and professional looking shots that appear to have more of a film look to them.
What is Depth of Field (DOF)?
Simply put, depth of field refers to the area of your scene that is in focus. As wikipedia states,
"Depth of field (DOF) is the distance between the nearest and farthest objects in a scene that appear acceptably sharp in an image."
It's important to first understand what it means to have a large depth of field (also called "deep focus") vs. a smaller depth of field (also called "shallow focus"). By creating a large depth of field, you will have an image where the entire image is in sharp focus. Most often, when using a standard camcorder in auto-focus mode, this is the effect that you will see. Conversely, shortening the depth of field (more easily achieved with a DSLR or camera with interchangeable lenses) will help you create an image where the main subject stands out more sharply and will be more in focus than the background or foreground. Using a DSLR camera gives you more control of depth of field.
Often times, using a more shallow depth of field will help you achieve a more professional, or cinematographic feel to your videos and this is what we're shooting for.
How to Achieve a Shallow Depth of Field
There are three things to keep in mind when managing your depth of field:
First, aperture refers to the opening in the lens that lets light into the camera and adjusting the aperture changes the brightness of the image being captured. When you let more light into the camera by opening up the aperture, you’re also drastically shortening the depth of field. When you're trying to make your focus more shallow, you'll want to open that aperture as far as it can go before you light your scene.
2) Focal length
Next is your focal length which refers to the distance from the optical center of the lens to the focal point. The higher the focal length, meaning the longer the lens is in millimeters, the shallower the depth of field will be and using a longer lens is one way to “crush the depth of field.”
3) Subject's distance from the camera
Just like using a longer lens, controlling the subject’s distance from the camera can affect the depth of field. By positioning your subject closer to the lens and keeping it in sharp focus, you'll get a shallower depth of field. As you roll the focus away from the lens the distance that is in focus deepens. So if your point of focus is two feet from the lens, you may only see two inches in focus around your subject, but if your point of focus is ten feet from the lens, much more of your scene will be sharp.
We hope this tutorial helps give you a better understanding of how you can use depth of field to produce more interesting shots that focus a viewer's eyes on the main subject while isolating it from its surroundings. Keep in mind that this is often a good look to go with when doing interview videos.
Question: When types of videos do you think are best suited for a more shallow depth of field look?
View The Full Video Transcript:
Hey, I’m Stephen Schweickart with vscreen where we make videos for businesses. Today, we’re going to talk about depth of field
For all you video newbies out there, depth of field refers to the area of your scene that is in focus. And, if you’re just getting into video production, you may not know that properly managing that focus is a key factor in achieving that Hollywood polish you AND your competition are missing. Step away from the amateurish look of having everything sharp, and learn to blur your background to give your action more POP.
There are three things to keep in mind when managing your depth of field: aperture, focal length, and subject distance from the camera. These all sound like big words… But, don’t worry, we’ll break them down into easy to chew Flintstones vitamin style chunks for you to swallow.
First, aperture refers to the opening in the lens that lets light into the camera. Any monkey can see that adjusting the aperture changes the brightness of the image being captured. But, it’s harder to tell that when you let more light into the camera, you’re also drastically shortening the depth of field. And, since you want your focus to be shallow, always open that aperture as far as it can go before you light your scene.
Next is your focal length. You don’t want to get a new camera, slap any old lens on there and just start blasting. You want to use the right lens in the right situation. Regardless of your aperture setting, if you film a scene with a 24 millimeter lens, chances are that pretty much everything is going to be in focus… and, if you’ve been following along, that’s exactly what we’re trying NOT to do. Back the camera away from your action and put a longer lens on it. You can look like a pro when you tell your crew you’re “crushing the depth of field.” That’s industry talk- and that one’s on the house. The higher the focal length, meaning the longer the lens is in millimeters, the shallower the depth of field will be.
And, now, the last and easiest to swallow factor is your subject’s distance from the camera. Simply positioning your action closer to the lens and keeping it in sharp focus will give you a shallower depth of field. As you roll the focus away from the lens the distance that is in focus deepens. So if your point of focus is two feet from the lens you may only see two inches in focus around your subject, but if your point of focus is ten feet from the lens, much more of your scene will be sharp.
Having the freedom to control these factors is paramount if you want to take your videos to the next level… so don’t just pick up the cheapest handy cam you can find. Do some shopping, make sure you have manual control over everything, and then make a video that doesn’t just give your viewers information… but looks damn good when it does it.
There are a lot of ways for your video to suck, don’t let the depth of field be one of them.