What Determines The Quality of a Smartphone Camera?

There is no doubt that the quality of smartphone cameras has improved over the years and continues to do so. However, what exactly is it that enables a mobile camera to take photos of great quality?

In this article, we will look at several factors that determine the quality of a smartphone camera.

The number and size of the pixels

Megapixels are perhaps one of the most popular (and spoken about) specs of a mobile camera. That is probably because a lot of people believe that a smartphone camera that has a lot of pixels will take better pictures than one that has fewer pixels. And although there is some truth to that, there’s so much more to it than just that.

The surface of a smartphone camera sensor has millions of light-capturing photosites, commonly referred to as pixels. The number of pixels in a mobile photo corresponds with the number of photosites/pixels on the camera’s sensor.

One million pixels are collectively known as a megapixel. That means that a 12MP mobile photo was taken using a phone camera sensor that has 12 million photosites/pixels (e.g. 4000px X 3000px). The total number of megapixels a camera has is known as the resolution.

The more pixels a camera has, the higher the resolution. That means that the images it produces will have sharp detail. That is great, especially if you want to print large-size copies of your mobile photos without losing picture quality due to pixelation.

However, the size of the pixels matters just as much, if not more. That’s because large pixels on the sensor can capture more light than small pixels. That makes for great photos, especially in low light conditions.

The size of the sensor

The sensor is perhaps the most crucial part of any digital camera. It is responsible for creating a digital image from the light it captures in its photosites.

The size of the sensor is critical in determining a smartphone camera’s quality because it dictates how many photosites can fit on the sensor and how big they can be.

That is a delicate balancing act between resolution and picture quality because the more pixels you pack onto a sensor, the smaller they get. That will give you images more resolution, but they might turn out less than pleasing due to digital noise in low lighting.

On the other hand, large sensors can house large photosites, which means the sensor can catch the much-needed light necessary to take quality images when the lighting is not great. But of course, the bigger the size, the fewer the pixels.

However, this is not necessarily a bad thing. Smartphone cameras don’t really need a ton of pixels on their sensors. That’s all just marketing hype. You can read the truth about smartphone camera megapixels here.

For more on smartphone camera sensors and how they work, click here.

Lenses and lens quality

The lenses of a mobile camera are responsible for taking the scattered light that enters the camera and focusing it on the sensor. For this reason, an array of quality lenses is necessary to avoid issues such as chromatic aberration and others.

It is difficult to tell the quality of a smartphone camera lens because you can’t see it or touch it. The only way you can check the quality of the lens is by taking test shots yourself or looking it up online from smartphone camera review sites.

Some smartphone companies have partnered with popular and reputable lens manufacturers as a way of boosting consumer confidence in their cameras. Nokia famously used Carl Zeiss optics for years, and Huawei famously uses Leica lenses in their phone cameras.

There is also a belief that the more lenses in a lens array, the better the pictures it will produce. To this extent, some smartphone companies (such as Xiaomi) have started indicating the number of lens elements their cameras have on their camera specs.

Aperture

By now, you should be aware of how important light is in mobile photography. Everything we’ve looked at so far has to do with capturing light or passing it through. Aperture is no different because it refers to the opening through which light enters the camera.

The aperture of a lens is measured and indicated in f-stops, for example, f/1.8. The lower the f-number, the wider the aperture. So, an f/1.4 aperture is wider than an f/2.2 aperture.

The wider the aperture, the better your mobile photos will be because, once again, smartphone cameras need as much light as possible to produce decent images.

On regular camera lenses, the aperture is adjustable, which allows you to adjust how much light can come through. On smartphones, however, the aperture is fixed. Some Samsung smartphones (the Galaxy S9 and S10 series) have a variable aperture, but this feature did not really catch on.

You can learn more about the smartphone camera aperture here.

The Image Signal Processor

The image signal processor (ISP) of a smartphone is a component found on the phone’s SoC (system-on-a-chip), an internal electronic system that controls the entire phone. The ISP is solely responsible for processing the light information captured by the sensor and turning it into mobile videos and photos.

This process includes fixes and adjustments to the captured image, such as noise reduction, white balance, lens error corrections, and more. A good ISP will produce clean, crisp images with colours that closely match those of the real world.

You can read more about the ISP and how it works here.

The power of a smartphone camera’s ISP is also evident in its computational photography capabilities. That refers to how a smartphone uses algorithms and software to make up for its physical shortcomings.

An example of this is the bokeh effect (blurred background) when taking portrait photos. Traditional cameras such as DSLRs can achieve this effect naturally, but smartphones cannot.

Other common examples of computational photography include HDR and night mode, which results in brilliant low-light mobile images from some phones. Hybrid zoom, which is a mix between optical zoom and digital zoom, is also a product of the ISP’s computational photography skills.

For more on computational photography and how it benefits mobile photography, check out this article.

Other specs

There are, of course, other mobile camera specs that, in one way or another, also impact the quality of a smartphone’s camera. Take image stabilisation, for example. Sure, you can do without it if you’ve got your phone on a tripod or other type of camera support system. But most people don’t have a tripod and those that do, don’t always have it with them.

The problem is holding your phone with your hands is not the steadiest of options. And if you have shaky hands, you could end up with blurry photos, especially if you’re using slow shutter speed.

Image stabilisation, particularly optical image stabilisation, helps to improve picture quality by counteracting any camera shake that could result in blurry mobile photos.

Another spec that can affect the quality of the photos a smartphone camera produces is the auto-focus, particularly the auto-focus method and speed. That is important because photos that are out of focus are not appealing at all.

I used to own a phone that took a very long time to focus on a subject. In a lot of cases, I’d end up with countless shots that are out of focus, or I’d miss the moment entirely because the camera was still trying to focus. It can be frustrating.

Conclusion

It takes more than just megapixels for a smartphone camera to take good pictures. There are several other factors that come into play, as outlined above. However, it takes more than just buying a phone with a camera that checks all the boxes in order for you to shoot amazing mobile photos with your smartphone.

If you are new to mobile photography and would like to improve how your mobile photos look, then I recommend you download my free ebook that will teach you five ways in which you can do so. It is simple and easy to understand, yet very informative. What’s more, it’s absolutely FREE! You can download it here.