Why is image sensor size so important in the camera cluster?

Now, the race for megapixels on smartphones is once again taking place, while the new sensor size is something that needs improvement. Huawei is a prime example of upgrading sensor size instead of raising the camera resolution.

With the P40 Series, Huawei proudly claims its product has a much larger image sensor size than its competitors. Meanwhile, Sony and Samsung are also gradually turning to sensor sizes instead of cramming megapixels. So why is it so important?

To understand why, we need to grasp some basic principles in photography: A large sensor will capture more light than a small size. More light means more beautiful pictures.

As bright as possible

The size of the sensor will determine how much light is absorbed into the lens.

Put simply, the size of the sensor will determine the amount of light that is absorbed into the lens, thereby contributing to increased image quality . While resolution plays a role in reproducing details, the amount of light captured by the sensor affects many factors such as white balance, wide contrast and sharpness. This is why DSLRs with a resolution of just 16MP or 20MP still take better shots than today's 108MP smartphones.

Most sensor sizes on phones are usually only 1 / 2.55 inch (about 1cm). While the new models are equipped with 1 / 1.7 inch larger sensor (about 1.49cm). And if you compare it, the sensor size on DSLR cameras is very large, about 1 inch (equivalent to 2.5cm) - much worse than on smartphones.

Google Pixel 4 in RAW photography mode in low light conditions, shutter speed of 1/20 sec, ISO 800.

The larger the sensor, the more light it will acquire, making the shutter speed, ISO and aperture parameters work better. Although manufacturers can use the exposure feature to meet this, but provided that the user must hold his hand and nothing objects go sideways. If not, the image will be blurred and encounter the phenomenon of "ghosts".

Nikon D3300 camera in RAW photography mode in low light conditions, shutter speed of 1/20 sec, ISO 800.

Similarly, the wide aperture lens, though helping to capture more light, is not available for every manufacturer. At the same time, large apertures usually don't work correctly in certain situations.

Another concept we need to know is photosite . These are millions of light-sensitive pixels equipped inside the sensor, arranged in different ways depending on the type. For smartphone image sensors, each pixel is a photosite.

The size of each photosite depends on the resolution and size of the sensor. The same sensor size but the smaller the photosite size, the higher the resolution. In contrast, the resolution remains the same, but the larger the photosite, the bigger the sensor size.

For small sized photosites, the acquisition of light information from one pixel may leak to adjacent pixels, causing noise every time you shoot in low light. Small sensor size and photosite will increase noise and reduce dynamic range.

Will a large sensor really increase image quality?

It is not true that raising the sensor resolution does not work. Because in bright light conditions, ultra-high resolution sensor such as 48, 64 or even 108MP will help photos with better detail.

But in return, in most cases, the camera usually shoots at low resolution to save space and for faster shutter speeds. However, cramming large resolutions into image sensors by manufacturers is not unintentional. They use algorithm to combine pixels and high megapixel dots to increase the ability to capture light.

These sensors, through pixel lumping, dramatically improve image quality in low-light environments, helping to reduce noise and retain better colors. In addition, they impact shutter speed, ISO, to help ensure sharp images.

Besides, the large sensor size also helps create better font removal effects, similar to professional DSLR cameras. Large sensors can use apertures, wide lenses to create a blur effect similar to small sensors, or use the same aperture, smaller lenses for better font removal effect.

This is just a small factor in the big whole

There are many other factors to create a quality camera system.

Besides the large sensor, there are many other factors to create a quality camera system. These include "good" lenses, powerful image processing chips or well-optimized algorithms, which help make the most of what the hardware has to offer.

In addition, camera quality on smartphones is increasingly being driven by advances in processing algorithms and machine learning. They are so powerful that they can beat smartphones equipped with a large number of dots. Even so, if both do not combine well, it still gives poor performance. In short, image sensor size is one of the essential components that make smartphone cameras work better .