What makes a good camera phone

Cell phone cameras are getting better and better with higher resolutions and more high-quality lenses for every scenario. However, in the large amount of manufacturer information, one can quickly lose track of which features are really crucial. We will show you the most important criteria for a good camera phone so that you can take the best possible cell phone pictures.

This article is part of a four-part series about cell phone photography. In this first part, we will focus on the most important features that make a good camera phone. The second part is about great camera phones that will stand out from the crowd in 2020. Part 3 will take you into the world of photography and give you tips and tricks for more beautiful pictures. Part 4 will show you the best ways to organize, edit and share your photos. Here you will soon find the links to the other parts of the series:

  • Part I: What makes a good camera phone?
  • Part II: The best camera phones 2020
  • Part III: How to take good cell phone pictures
  • Part IV: Organize, edit and share photos

Many criteria for good camera phones

Many criteria for good camera phones

It is not so easy to choose the ideal smartphone these days. If special requirements are added, for example in terms of display, performance or camera, you have to look carefully to see which cell phone meets your expectations. If you’re interested in a smartphone with a high-quality and versatile camera, you usually can’t avoid expensive devices. The manufacturers usually equip their flagships with the best lenses. There are a few aspects to consider here that are decisive for the quality of the camera.

Different lenses for every scenario

Versatile wide angle lens

For a few years now, manufacturers have been using multiple sensors in their camera systems. So when looking for a good camera phone, you should pay attention to the different lenses. Usually the main sensor is a normal wide angle lens with a high resolution and a low aperture to take nice pictures in all everyday scenarios. Combined with image stabilization, a good autofocus and a night mode, you can take nice pictures of any subject even in moving scenes and in the dark. In most situations you use the main lens, so you should pay special attention to high quality.

Many smartphones rely on sensors from Sony. One example is the extremely popular IMX586 with 48 megapixels, which is found in some smartphones from Samsung, Xiaomi, OnePlus and others. In addition, manufacturers such as Sony, Nokia and Huawei are working with well-known professional photography brands such as Zeiss and Leica to install perfectly matched lenses.

Long distance shots with the telephoto lens

Long distance shots with the telephoto lens

One lens that has become a standard is the telesensor. It has an optical zoom and is used to bring distant lenses closer. Previously, enlarging an image section with a smartphone was only possible using the lossy digital zoom. This is not a real zoom lens, since you can only switch between the different sensors with fixed focal lengths. For example, the telephoto lens has a longer focal length than the other sensors – usually over 50 mm. The lens is perfect for traveling and for portraits.

Other sensors

The ultra wide angle lens is another sensor used in many cell phone cameras. Unlike the telephoto lens, it offers a short focal length, usually less than 20 mm, and can capture large subjects such as landscapes.

Some cell phone cameras have a macro lens to capture small subjects like insects or details of objects. These sensors are nice features to get some nice close-ups. Currently, however, the lenses in most camera phones have a low resolution and are more of a gimmick.

One sensor that cannot be used to take pictures by itself, but is built into many cell phones and supports the other lenses, is the depth sensor. It is often a time-of-flight camera (ToF), which measures the distance to objects and thus provides information for the depth of field. 

This can create a nice bokeh effect.

This can create a nice bokeh effect

For the optimal recognition of light values to be able to provide even more details, some camera phones have a light-sensitive monochrome sensor. This sensor does not capture color values and can therefore support the other lenses in precise brightness detection and HDR photos. Some devices like the Nokia 9 PureView even support native black and white photos. Unlike sensors with color detection, color is not removed from the images afterwards, resulting in stronger and more “natural” results.

The importance of resolution

Meanwhile the lenses of cell phone cameras and in particular the wide angle sensors offer very high resolutions – partly over 100 megapixels! A high resolution means that photos can be clearly more detailed, since they contain substantially more picture information. In retrospect, you can enlarge the pictures and for example print out only a small section of the image in large format without having to put up with highly visible quality losses.

Find the right resolution

A typical value for cell phone cameras are 12 megapixels. This is about six times the resolution of a Full HD image (1080p, about 2 MP) and 2.4 times the resolution of QHD (1440p, about 5 MP), the typical resolutions of many displays. Even for a 4K or UHD television (2160p, approx. 8 MP) 12 megapixels are sufficient. Even professional SLR cameras work with resolutions in the middle to high two-digit megapixel range. A reasonable resolution is therefore indispensable for capturing multifaceted and small motifs as well as for improved digital zooming in post-processing and display on high-resolution screens.

Videos are normally recorded on current top smartphones in 4K (UHD) and can be viewed well on the big screen. Some cell phones now even offer an 8K resolution (UHD-II) for filming! For this you need a lens with at least 33 megapixels (4320p).

High quality sensors

High quality sensors

One should not be irritated by high megapixel numbers. An extreme value only says something about the quality of the sensor and thus the photos to a limited extent. In order to get beautiful pictures without strong lens distortions (distortion) or image noise, which convince with vivid colors and precise sharpness, high-quality lenses and a well processed sensor are indispensable.

Nowadays, smartphones are equipped with powerful CMOS sensors (active pixel sensors), which create very good photos despite their small size in a limited package. The larger the sensor area, the more flawless the images are usually, since each individual pixel can capture more light. Therefore, the small sensors with high resolution use pixel binning, among other things. In low light conditions, several pixels can be combined to form a block to achieve higher light sensitivity and avoid interference. This way, the photos have a lower resolution, but gain in quality.

Reliable information about camera phones

Computer and cell phone magazines and especially the DXOMARK team provide reliable information about the quality of camera phones and their lenses and sensors. In addition to the detailed information on our website in the Revwr and in the continuously updated camera phone best list, the DXOMARK website offers a good overview of the best smart phone cameras. There you will find transparent reviews and an easy to understand score that is respected throughout the industry.

You can find out which devices do particularly well in Part II: The Best Camera Phones 2020.

Great shots even in motion and darkness

Great shots even in motion and darkness

Low aperture

A large number of software and hardware features are responsible for the high quality of today’s cell phone photos. A well-known element from classical photography, which is also very important for cell phone lenses, is a low aperture. This specification says something about how much light can enter the sensor, i.e. how fast a lens is and what depth of field is possible.

Maximum aperture values around f/2.0 and lower are common on modern smartphones and allow you to take well-exposed pictures even in the dark because you can choose a shorter exposure time. The lower the f-number (e.g. f/1.5), the stronger the background blur and bokeh. This allows subjects to stand out from their background, which is perfect for portraits.

Good image stabilization for wobble-free shots

In order to be able to take calm photos and especially videos, you need good image stabilization. Here we distinguish between electronic (EIS) and optical image stabilization (OIS). EIS uses software to provide a more stable image and relies on the accelerometer to detect the movement of the cell phone. This can be very helpful with shaky shots, but the image quality often suffers because EIS can sometimes produce unnatural distortion and the software uses cropping to cut away part of the photo/video as a buffer.

Optical Image Stabilization (OIS) is the gold standard to get smooth images. This is where the hardware comes into play: a gyroscope detects in which direction the smartphone is moved and adjusts the camera position in the opposite direction. This proves to be extremely practical in the dark and for telephoto lenses. The OIS is usually only used with more expensive smartphones and then not with all lenses.

The perfect mix for truly outstanding cell phone photos is Hybrid Image Stabilization (HIS). It combines OIS and EIS and can therefore only mechanically produce a stable image that is subsequently optimized by the software. This is especially practical for videos as well as 

HDR images and long time exposures.

There are also smartphone accessories such as tripods and gimbals with which you can obtain stable shots. These are discussed in more detail in Part III: How to take good cell phone photos.

Precise autofocus

Precise autofocus camera phones

In order to be able to take good photos of moving and hardly recognizable motives fast, one needs a reasonable autofocus. Modern smartphones rely on so-called PDAF (Phase Detection Autofocus) or laser autofocus to quickly focus on a subject in all situations. A good autofocus is characterized by the fact that it works reliably even in action and in the dark. Thus, with the help of AI-optimized object tracking, you can always have the desired subject in view.

Bright and natural flash

The classic method to get well lit photos is, as is well known, the flash. Over the years, better and better flashes have been built in with bright LEDs and precise and adaptive color temperature like Apple’s True-Tone Flash. Pictures that are illuminated by a flash are bright and therefore enable sharp pictures with short exposure times even in the dark. However, they have an unnatural look because they brighten a subject in the foreground and swallow the background. This can create a desired aesthetic, but in most cases disturbs the atmosphere of the image.

Different modes and other features

Another criterion for a good camera phone is the presence of different modes in which your photos are optimized according to the situation. In addition to the portrait mode, the night mode, for example, is especially useful for brightening dark areas and still getting a sharp picture. Good HDR (High Dynamic Range) shots are another plus point for taking particularly attractive, multi-faceted photos. They are composed of several (usually three) under- and overexposed images, whereby all light and dark areas are adjusted to create a harmonious image result.

The Panorama mode is ideal for landscapes and large crowds of people. Here, several photos from one movement are joined together to create a large image. To compress shots into short videos over a longer period of time and give them that certain something, many smartphones have a time-lapse function. This usually requires a stable positioning over a tripod.

Exactly the opposite is achieved with slow-motion shots, which slow down entertaining moments in an impressive way. Current smartphones achieve amazing frame rates of 960 fps. The Huawei P40 Pro and Mate 30 Pro even offer an overwhelming 7,680 frames per second (yes, you read correctly: seven thousand six hundred and eighty)! This requires extreme computing power, which only such top-of-the-line devices are capable of.

The Pro mode, in which the elements exposure time, aperture, ISO and focus can be set manually and individually on most smartphones, should also be emphasized. So with the right know-how and a little extra equipment, you can produce extremely professional photos.

Sufficient power and memory

Fast and modern processor

Fast and modern processor

As we have already indicated, modern camera phones require extremely powerful hardware to enable functions such as 8K video and super slow motion without problems. That’s why the latest Android phones, for example, rely on the Qualcomm Snapdragon 865 and Apple on its superior A13 chip. Only the flagship phones are usually equipped with these premium processors, which is why good camera phones often come at a price. Current chips from MediaTek, Exynos (Samsung) and Kirin (Huawei & Honor) also perform flawlessly in processing complex camera software.

Good chips can be recognized by multiple cores with high clock rates above 2.5 Gigahertz (GHz). For example, a CPU (Central Processing Unit) with 1 GHz per second can process one billion current pulses. So the more gigahertz, the more processing steps a processor can perform per second. The performance in gigahertz accordingly describes the speed of the processor, but does not necessarily say anything about the quality of the chip.

The number of cores is also decisive. Most processors today have several cores and are accordingly called Hexa- (6) and Octa-Core (8). The more cores a CPU has, the more tasks it can do simultaneously per second. With multi-core processors, the computing load is distributed evenly among all cores, which leads to better performance.

Sufficient memory

In order for the processor to work properly and to have enough buffer for large tasks, a smartphone needs enough memory (RAM). Current top smartphones often offer eight gigabytes of RAM. The Samsung Galaxy S20 Ultra 5G even offers 16 GB RAM in the highest configuration, which can keep up with many laptops. The amount of RAM is a good indicator for complex computing power. However, some manufacturers such as Apple combine lower values with a sophisticated hardware architecture and thus outperform much of the competition. For this reason, memory is not a decisive factor in warfare with some well-processed devices.

As much memory as possible

If you take a lot of photos and videos, you need a lot of space. 64 or 128 gigabytes have become the standard for higher priced devices. For most users this amount of memory is sufficient. Those who need more should get a smartphone with at least 256 GB or use a cell phone with expandable memory. Samsung’s Galaxy S and Note series are known to offer a lot of storage space, which can even be increased with a microSD card.

Alternatively, you can save your recordings in the cloud. There is a wide range of providers that you can fall back on. For Android users, Google Drive or the manufacturer’s own services are available. iPhone owners can rely on the well-integrated iCloud. But other products such as OneDrive from Microsoft or Dropbox are also good options for cross-device storage. With all these services, one should pay attention to the price-performance ratio of the available storage space, the flexible usage options with different end devices and, of course, data protection.

You can learn more about how to store and organize your photos properly in Part IV: Organizing, Editing and Sharing Photos.

Good audio and video playback

To be able to play your photos and videos in good quality, you need a smartphone with a good display and reasonable speakers. Although you can display the results on a larger screen like a 4K TV, your phone should also have suitable video and audio features for everyday life and for enjoying memories together.

A good display requires at least a Full HD resolution (1080p), but for high-resolution material, displays with Quad HD (1440p) are recommended. Size is also important here, as photos and videos can be viewed much better on a 6.5-inch display than on smaller devices. The display technology is also decisive. An OLED display gives a much better picture with stronger colors and more intense black than an LCD. Other features such as HDR10+ and a high frame rate (e.g. 90 Hertz) can also have a great influence on the quality of the image reproduction.

More information about the different displays and their resolutions can be found in our guide article: What are the differences between the display types and resolutions?

Last but not least, speakers suitable for videos are important. Some manufacturers are saving money here, but especially stereo speakers with a powerful sound make a big difference. You can also find a lot of information about the audio quality of different cell phones from the colleagues at DXOMARK.

There are many aspects to consider when choosing a good smartphone camera: from the different lenses to high-resolution sensors and various photo functions to performance. You have now gained a good overview of which of these features are crucial for a good camera phone. You can find out which devices meet these criteria and stand out particularly in Part II: The Best Camera Phones 2020.

In addition, some features and possibilities were presented that require a certain amount of know-how in order to use them properly. Part III: How to take great pictures with your camera phone shows you how to use all this information correctly. In Part IV: Organizing, Editing, and Sharing Photos, you’ll learn how to manage your photos.