How Does a Depth Sensor Camera Work?

How Does a Depth Sensor Camera Work?

Depth sensor cameras are becoming more and more popular in the world of photography. But what exactly are they, and how do they work?

Depth sensor cameras are basically two cameras in one body. One is a traditional RGB camera, while the other is an infrared (IR) camera. The IR camera is used to measure the distance between the camera and objects in the scene. This information is then used to calculate the depth of field for each image [1].

The advantage of using a depth sensor camera is that it can create images with a shallow depth of field, even in low-light conditions. This means that you can focus on a specific subject, while the background remains blurred. Depth sensor cameras are also great for video applications,  as they can create a realistic three-dimensional effect.

In this blog post, we will explore the inner workings of depth sensor cameras and discuss how they are changing the landscape of photography. Stay tuned for an in-depth look at these amazing devices!

How a Depth Sensor Works – Quick Description

A camera’s depth sensor blurs a distracting background, turning background light points into softer circle points. This creates a shallow depth of field (blur) between the subject and the background.

How a Depth Sensor Works – Quick Description

The depth sensor in a camera, as the name implies, detects depth. With beautiful effects and augmented reality, these depth sensors blur the background and make the subject stand out from it [2].

This is a very important development in the world of photography.

It gives you more control over your photos and opens up new possibilities for creativity.

A depth sensor uses an infrared (IR) light projector and an IR camera to sense the distance between objects. The projector sends out a grid of IR dots, and the camera measures how long it takes for each dot to bounce back. By knowing the speed of light, the depth sensor can calculate how far away each object is.

The advantage of this system is that it works in any lighting conditions, including low light and even complete darkness. It also doesn’t require any special calibration like some other depth-sensing systems.

Depth sensors are used in a variety of applications, including video games, security systems, and automotive safety. They’re also being used more and more in consumer devices like smartphones and tablets.

Today’s depth sensors are being supplanted by new ultra-wide and telephoto lenses that allow you to get better portraits. These newer lenses may capture people more effectively, so you won’t need another camera. If a telephoto camera is sufficient, you might not need a depth sensor at all. In addition, you might be interested in telephoto vs. zoom lens comparison.

Depth sensors are an important tool, but they’re not the only way to create beautiful photos. With the right lens, you can get great results without one. It’s up to you to decide which system is best for your needs.

TOF Depth Sensors

Time of Flight (TOF) is a term that refers to the time it takes a light ray to travel from one point to another [3]. It determines how far apart two points are based on the length of time it takes for light to travel between them. The camera may now take not only a portrait but also 3D photos, which can be 3D printed. The camera may also determine the subject’s distance. Most cellphone companies are using TOF sensors instead of previous depth sensors.

TOF Depth Sensors

The TOF depth sensing is genuine, and it aids in 3D photo capturing. TOF sensors are now available on smartphones such as the Galaxy S20 Ultra and S20+. These cameras are able to sense the subject’s depth and distance from the backdrop, as well as its background, and take your photography skills to a new level.

Do Depth Sensors in Smartphones Actually Work?

We’ve all seen the commercials. A new smartphone is released with a depth sensor camera, and we’re told that this will revolutionize photography. But how does a depth sensor actually work?

There are two main types of depth sensors: active and passive. Active depth sensors emit a light source, usually in the infrared spectrum, and then measure the time it takes for that light to bounce back off of an object. This information is then used to calculate the distance to the object. Passive depth sensors, on the other hand, use existing light sources, like those from the sun or artificial lights, to create a three-dimensional map of an area.

So which type of depth sensor do smartphones use? The answer is both. Most newer smartphones have what’s called a time-of-flight sensor, which is an active depth sensor. This is combined with a passive depth sensor, usually referred to as a structured light sensor, to create a more accurate depth map.

Do Depth Sensors in Smartphones Actually Work?

With the release of the iPhone X, Apple introduced a new type of depth sensor called the Face ID camera. This uses infrared light to map your face in three dimensions, which is then used for security purposes [4].

Aperture Priority Mode

Don’t worry if your smartphone camera lacks a dedicated depth sensor; it was useless long ago. To create a Bokeh effect, set the aperture to the maximum value stated in your camera’s specifications and use aperture priority mode. When it comes to shutter speed, you must use auto mode.

Keep in mind that if the shutter speed appears to be slower than 1/125th of a second, you’ll need a tripod.

Achieving a shallow depth of field requires that your subject be close to the camera and that there’s a significant distance between your subject and the background. The closer your subject is to the camera, the easier it will be to achieve a shallow depth of field.

You can also use editing software like Adobe Photoshop to create a Bokeh effect by using the blur tool. This can be done after you’ve taken the photo or even on a photo that you found online.

Focal Length Adjustment

You may also use a longer focal length to make the background blurry. Don’t be perplexed if you hear adjusting the focal length referred to as zooming in or out; it’s a fancy way of saying that [5]. The focal length adjustment is usually on the lens itself.

Focal Length Adjustment

Some phones have a second camera with a longer focal length. If you don’t have one of those, you can still use the portrait mode by cropping the image after taking it. The trade-off is that you’ll lose some of the resolutions, but it’s worth it for a good bokeh effect.

Read more posts to improve your photography skills:

How Does a Depth Sensor Camera Work – Indicators Explanation

Depth sensor cameras utilize advanced technology to capture depth information of a scene, allowing for the creation of 3D depth maps. These cameras are crucial in various applications, such as augmented reality, robotics, and gesture recognition. In this table, we will explore the key indicators that play a vital role in understanding how depth sensor cameras work.

Indicator Description
Depth Range The depth range refers to the minimum and maximum distance from the camera at which it can accurately measure depth. A wider depth range allows the camera to capture objects both near and far from its lens.
Depth Accuracy Depth accuracy signifies the precision with which the camera can measure the distance to objects in the scene. High depth accuracy is crucial in applications that require precise depth information.
Field of View (FOV) The field of view represents the extent of the scene that the camera can capture in a single frame. A wider FOV allows the camera to cover more area, providing a broader perspective.
Technology Used The underlying technology used in the depth sensor camera affects its performance. Common technologies include Time-of-Flight (ToF), structured light, and stereo vision.
Light Source Depth sensors often utilize a light source to illuminate the scene for accurate depth measurement. The type of light source employed can impact the camera’s performance in various lighting conditions.
Application The specific application for which the depth sensor camera is designed greatly influences its features and capabilities. Some cameras are optimized for smartphones, while others are tailored for robotics or gaming.


  1. Depth Range: This indicator determines the range of distances over which the camera can measure depth accurately. A larger depth range allows the camera to capture objects at varying distances, making it versatile for different applications.
  2. Depth Accuracy: Depth accuracy reflects the precision of the camera’s depth measurements. A camera with high depth accuracy is essential in applications that require fine-grained depth information, such as object recognition or virtual object placement.
  3. Field of View (FOV): The field of view indicates the breadth of the scene that the camera can capture in a single shot. A wider FOV is advantageous in scenarios where a broader perspective is necessary, like in immersive augmented reality experiences.
  4. Technology Used: Depth sensor cameras utilize various technologies like Time-of-Flight (ToF), structured light, or stereo vision. Each technology has its strengths and weaknesses, affecting factors such as accuracy, range, and cost.
  5. Light Source: To measure depth accurately, some cameras employ a dedicated light source, such as infrared illumination. The type and intensity of the light source play a role in the camera’s performance under different lighting conditions.
  6. Application: Depth sensor cameras are designed with specific applications in mind. For instance, a camera optimized for smartphones may prioritize compactness and power efficiency, while a camera for robotics may focus on robustness and precision.

Understanding these key indicators helps users and developers choose the most suitable depth sensor camera for their intended use, ensuring optimal performance and functionality in their respective applications.


How do I know if my depth sensor is working?

If you have a computer with a depth sensor camera, you can check if it’s working by looking at the device manager. If the camera is working properly, it should be listed under “Imaging devices”. If it’s not working, then there might be a problem with your driver or your hardware.

To test if your depth sensor is working, you can use the Kinect Viewer tool that comes with the Kinect SDK [6]. This tool will show you a live view of what the depth sensor sees, and it will also give you some information about the current frame rate and resolution.

If you’re having trouble getting your depth sensor to work, make sure that you’ve installed the latest drivers for your device. You can usually find these on the website of manufacturer.

What does the depth camera do on a phone?

The depth sensor camera is used to estimate the distance to objects by using infrared light. This information can be used to create a three-dimensional map of the environment. The camera can also be used for hand gestures and facial recognition.

Depth sensor cameras are not new technology, but they are becoming more common in smartphones. The iPhone X was one of the first phones to include a depth sensor camera. The Google Pixel and Samsung Galaxy S20 series also have depth sensor cameras.

The depth sensor camera uses an infrared projector and an infrared camera to emit and detect infrared light. By measuring the time it takes for the light to bounce back, the phone can calculate how far away an object is.

Is depth and telephoto the same?

A telephoto lens, unlike a depth sensor, does an excellent job at compressing the perspective while also providing crispness to the photograph. Using a telephoto lens, you may obtain a minimal and abstract composition with black mist and a single point of focus [7].

Depth sensors, on the other hand, are not very good at compressing the perspective. Instead, they excel at capturing three-dimensional (depth) information. This is because depth sensors use an infrared (IR) light source and a special IR camera to capture images.

The way it works is that the IR light source projects a grid of IR dots onto the scene. The depth sensor’s IR camera then captures how these dots are distorted as they reflect off objects in the scene. By analyzing this data, the depth sensor can determine how far away each point in the scene is from the camera.

What is a 2MP depth sensor?

The dedicated macro lens allows users to get up close to the things while capturing the photos, and the dedicated 2MP depth sensor aids in real-time depth detection for a better Bokeh effect.

For example, OnePlus has used similar technology in its recently launched OnePlus Nord phone. The phone makes use of a time-of-flight (TOF) sensor for bokeh shots as well as for detecting objects and surfaces for AR purposes.

The Chinese company has also included a time-of-flight (ToF) sensor which uses an infrared laser to measure the distance between the subject and the camera. This, in turn, helps create a realistic depth of field effect.

Why is my true depth camera not working?

If your True Depth camera isn’t working, it might be due to a number of different reasons. First, make sure that there’s nothing blocking the sensor, such as dirt, dust, lint, or a case. If that doesn’t fix the problem, try restarting your device. If that still doesn’t work, contact Apple Support.

How do you shoot depth of field?

The shallow depth of field is created by using a low f-number, or f-stop, such as 1.4 to 5.6, to let in more light when taking photographs. It’s very difficult to focus on many things at once. This is the range in which your attention may be focused between a few inches and a few feet. You can blur the foreground or background of your picture, depending on your topic and area of interest point [8].

A deep depth of field can be created by using a high f-number, such as f/11 to f/22. This will result in everything from a few inches in front of your camera all the way to the horizon being in focus.

You want to make sure that you have enough light when taking pictures with a high f-stop because a small aperture means less light is entering the camera.

How does a depth sensor camera work?

Depth sensor cameras work by emitting infrared light or laser beams onto the subject and measuring the time it takes for the light to bounce back to the camera. This time-of-flight (TOF) or structured light technology allows the camera to create a depth map of the scene, indicating the distance of objects from the camera. This information is then used to generate a 3D representation or add depth effects to images.

What is the purpose of a depth sensor in a camera?

The primary purpose of a depth sensor in a camera is to enable advanced depth perception. By accurately measuring the distance between the camera and various objects in the scene, the depth sensor allows for the creation of realistic bokeh (background blur) effects, improved augmented reality experiences, accurate facial recognition, and other depth-based features in photography and mobile applications.

How does a time-of-flight (TOF) depth sensor work?

A time-of-flight depth sensor works by emitting a pulse of light, such as infrared or laser, towards the subject. The sensor then measures the time it takes for the light to bounce back to the camera. Since light travels at a known speed, the camera can calculate the distance between itself and the objects based on the time it takes for the light to return. This data is used to create a depth map of the scene.

What is structured light technology in depth sensors?

Structured light technology is another method used in depth sensors to measure distance. It involves projecting a pattern of infrared light onto the subject. The distortion of this pattern on the objects is then analyzed by the camera’s sensor. Based on the distortion, the depth sensor can determine the object’s distance from the camera, allowing for the creation of depth maps and other depth-related features.

How is depth information used in photography?

Depth information in photography is used to create various artistic effects. By knowing the distance of objects from the camera, photographers can apply realistic background blur (bokeh) to isolate subjects, resulting in a professional-looking portrait. Depth information is also utilized in post-processing to add 3D effects, such as changing the focus point or altering the background.

What are the applications of depth sensor cameras?

Depth sensor cameras have a wide range of applications. They are commonly used in smartphones for facial recognition, bokeh effects, and augmented reality experiences. In robotics, depth sensors help with object detection and navigation. They are also utilized in the automotive industry for driver-assistance systems and in various industrial applications like 3D scanning and measurement.

Can depth sensor cameras work in low light conditions?

Depth sensor cameras that use time-of-flight (TOF) technology can struggle in very low light conditions since they rely on emitting and detecting light. However, some depth sensors equipped with infrared illuminators can still function reasonably well in low light environments. Structured light depth sensors may also perform better in low light as they project their own light pattern onto the scene.

How does a depth sensor differ from a regular camera?

A regular camera captures a 2D representation of a scene, whereas a depth sensor camera provides additional depth information, enabling the creation of 3D models or depth maps. This additional data allows for various depth-based effects and applications like augmented reality and accurate distance measurements, which are not possible with a standard camera.

Are all smartphones equipped with depth sensor cameras?

No, not all smartphones have depth sensor cameras. Depth sensors are more commonly found in mid-range to high-end smartphones, particularly in devices geared towards photography enthusiasts or those with augmented reality capabilities. Budget smartphones may not include a dedicated depth sensor, relying instead on software-based depth effects using multiple camera lenses.

How accurate are depth sensor cameras?

The accuracy of depth sensor cameras can vary depending on the technology and the quality of the sensor. Time-of-flight (TOF) depth sensors and structured light depth sensors are generally more accurate than software-based depth effects using dual cameras. High-quality depth sensors can achieve accuracy within a few millimeters, making them suitable for precise applications like 3D scanning and measurement.

Useful Video: Depth Cameras