How do phone cameras work? Unlocking the secrets behind mobile photography.
With just a tap, your phone turns everyday moments into frame-worthy photos – thanks to a tiny powerhouse of hardware and algorithms.
Improvements in hardware mean smartphone cameras have come a long way since they were created. The main components are the lens, image sensor, and image processing software. Let’s break down what’s going on inside to understand how phone cameras work.
The lens focuses light onto the image sensor, which turns it into an electrical signal. Some smartphones use one lens to capture the entire image, while others use multiple lenses that have different purposes:
Wide-angle lenses allow you to capture more of a scene in your photo.
Telephoto lenses help you zoom in on one area.
Several lenses can work together to create better, sharper images.
Focal length is the distance between the lens and the image sensor, measured in millimetres. This creates the camera’s field of view – the amount of a scene the camera can capture.
A shorter focal length creates a wider field of view, so you can see more of the scene.
A longer focal length results in a narrower field of view, essentially focusing in on a smaller area.
Smartphone cameras can have different lenses with different focal lengths. It’s common to have three lenses: the main lens, telephoto lens and an ultra-wide lens.
The image sensor is made up of millions of pixels that convert light into digital data to create an image. A larger sensor can capture more light, meaning better image quality, especially in low-light conditions.
Larger pixels on the sensor can improve low-light performance by creating sharper images.
Smartphone cameras often have smaller sensors than professional digital cameras. That results in shorter focal lengths, so more of the scene stays in focus.
Some smartphones use software to blur backgrounds and create the effect of a shallow depth of field.
The aperture is the opening in the lens that lets light reach the image sensor. This affects light sensitivity. This phone camera hardware also controls how sharp the background of a photo is and where this sharpness starts, known as the depth of field.
Aperture is measured in f-stops, an f followed by a number. The larger this number is, the narrower the aperture.
A narrow aperture, such as f/8, creates a large depth of field, keeping more of the scene in focus.
A wide aperture, such as f/1.8, creates a shallow depth of field, blurring the background.
Instead of changing the opening in the lens, most smartphone cameras use technology to produce professional-looking photos with blurred backgrounds and a shallow depth of field.
Portrait Mode on Pixel phones uses machine learning to estimate depth and blur the background, putting the focus on the subject of your photo.
The flash provides additional light when shooting in dark conditions. There are different types of LED flashes:
Single-LED flash: One LED light.
Dual-LED flash: Two LED lights that can be different colours, allowing for more accurate colours.
Variable LED flash: A variable flash can adjust its output based on lighting conditions to create a more natural-looking result.
To understand how phone cameras work, it’s useful to know what’s going on in the background when you take a photo. Let us explain camera specs and the image processing features that make smartphone images look their best.
The image processor is a dedicated chip that takes signals from the image sensor and transforms them into the final picture. The processor’s software uses some of the features and enhancements below.
RAW images contain unprocessed data directly from the image sensor, offering more flexibility for editing. JPEG images are compressed and processed, resulting in smaller file sizes but less editing flexibility. Pixel phones can shoot in both RAW and JPEG (or both at the same time with the RAW+JPEG option), giving you more freedom when
From slower software-based contrast detection to faster phase detection autofocus (PDAF), smartphone cameras automatically focus to create sharper images. PDAF systems compare light intensity from different sensor areas to quickly adjust focus.
Noise reduction software removes the unwanted grainy look in images, especially photos taken in low light. Smartphone cameras also enhance the edges and details in an image to make it appear clearer.
Pixel phone cameras have great low-light performance thanks to
OIS physically stabilises the lens or image sensor to compensate for shaky hands, resulting in sharper images and smoother videos. EIS reduce camera shake electronically, often cropping the image slightly.
Computational photography uses software to enhance images in ways that wouldn’t be possible with traditional photography. Pixel phones use
So, that’s the magic behind smartphone cameras – powerful hardware, smart software, and a whole lot of behind-the-scenes processing working together each time you take a photo.
Not available for all cameras, apps or modes.