The camera has become the biggest selling point of today’s smartphones. As a result, a lot of people want to know what type of camera a phone is packing before they even consider buying it.
Sites like GSM Arena provide the full lowdown on smartphone camera specs, yet very few people actually understand what any of it means.
Terms like megapixels, OIS, HDR, and others are often thrown around when referring to mobile cameras. It can get really confusing, especially when all you want to know is which camera phone will satisfy your needs.
This article will help you make sense of it all, and make it easier for you to decide what’s good enough for you.
1. Megapixels
Camera specs of the Xiaomi Mi 10 Pro 5G (released February 2020)
Megapixels refers to the number of small picture elements in a photo called pixels. These are usually really tiny dots or squares that make up a complete digital image. A million pixels are known as a megapixel.
Megapixels are essentially the building blocks of a digital image. These blocks are arranged in rows and columns similar to a chessboard but on a much, much smaller scale. (Refer to ‘Pixel size’ below)
Megapixels may also refer to the number of photosites found on an image sensor, that capture light information to produce the image. If an image has 12MP, it is very likely that it was captured on a sensor with twelve million or more photosites. More on this later.
Remember, there are a million pixels in one megapixel. Therefore, a 12MP photo is made up of twelve million pixels. This is known as the ‘resolution’. The more megapixels a smartphone camera has, the higher the resolution of the photos it produces.
A high resolution camera (such as that of the Xiaomi Mi 10 Pro) can give you an image with more clear detail than a low resolution camera.
This means that if you were to print your smartphone photos, you’d be able to print large high-quality photos that aren’t pixelated. Basically, you could print artistic prints for your wall from your mobile pictures.
Today, there are some smartphone cameras with high megapixel counts, some as high as 108MP. But do not be misled by super-high megapixel counts. Megapixels alone DO NOT guarantee better camera performance. There are many other factors that affect picture quality.
To learn the real truth about megapixels, click here.
2. Sensor size
Samsung Galaxy S20 Ultra (released March 2020) camera specs
A mobile camera’s image sensor is a device that takes the light that enters the camera and produces a digital image from it. It’s pretty much the replacement for photographic film.
The size of the sensor is important because the bigger the sensor, the more light it can potentially receive. The more light it can receive, the better the picture quality. This is especially important in smartphone cameras because of their size limitations.
Smartphone sensors are much smaller than those found on standard, full-frame cameras. Source: bbc.com
The size of the sensor refers to its physical size, but when it comes to the actual numbers of it all, things can get a little bit confusing. Different manufacturers tend to use or state different methods of measurement.
The size of a smartphone sensor is commonly expressed using inches (“) or fractions of an inch. To date, no smartphone camera has had a sensor bigger than 1”. At 1/1.33”, the Samsung Galaxy S20 Ultra’s primary camera sensor is one of the biggest smartphone camera sensors on the market today.
Without getting too technical, what you need to understand with smartphone camera sensors is that the closer to a full inch (1”) you get, the bigger the sensor is. Why this is important is because the size of the sensor has an impact on the size of the pixels.
As mentioned previously, the surface of a sensor contains millions of photosites also known as pixels which are responsible for capturing the light. Part of the reason why a camera with a big sensor takes better pictures is that it can pack more pixels that are bigger in size than those found on a smaller sensor.
To learn more about smartphone camera sensors, the way they work, and how they impact your mobile photos, click here.
3. Pixel size
Huawei P40 Pro 5G (released April 2020) camera specifications
We’ve already spoken about pixels and megapixels a few times in this article. What this particular spec refers to is the size of each pixel found on the sensor.
These are measured in micrometers, often referred to as microns. The symbol for microns is ‘µm’ or just ‘µ’. One millimeter (1mm) is equal to 1 000 micrometers (1 000µm).
The pixel size is one of the important things you need to look out for when buying a phone for its camera. A camera with a sensor that has large pixels is more desirable because the bigger the pixels are, the more likely you are to get great picture quality from the camera.
A mobile camera sensor with a pixel size of 2.4µm (such as the one in Huawei’s P40 Pro) is far superior to one with a tiny pixel size of only 0.8µm. That’s because large pixels on the sensor gather more light and are less likely to produce digital noise.
This is ideal for taking photos in low lighting. A mobile camera with larger pixels is more likely to take brighter and sharper photos at night than one with small pixels.
But because the size of the sensor is fixed, the more pixels you try to fit onto it for more image resolution, the smaller they get. That’s not really a good thing because smaller pixels are more susceptible to noise, especially in low light.
Bigger pixels, on the other hand, can receive more valuable light information and therefore can ultimately perform better in low light.
In other words, a 1/2.5-inch smartphone camera sensor with 12 million pixels (12MP) has bigger pixels than the same sensor with 20 million pixels (20 MP) crammed into it. In this case, the 12 MP sensor could potentially outperform the 20 MP one in low light. However, the 20MP camera will have more resolution.
4. Aperture
Specifications of the Samsung Galaxy S10 (released March 2019) mobile camera
Typically, aperture is the adjustable opening between the lens and the sensor that controls how much light reaches the sensor. How wide or narrow the aperture is is expressed in f-numbers. A low f-stop (e.g. f/2) means a wider aperture than that of a higher f-number (e.g. f/16).
The wider the opening, the more light will come through. The smaller the opening, the less light will come through. In smartphone cameras where getting as much light as possible is paramount, having the widest aperture possible is very ideal.
The lower the f-stop, the more light your smartphone camera can capture. And, obviously, more light means better pictures.
Notice in the beginning I said ‘typically, aperture is adjustable’. That’s because it’s how aperture works on traditional cameras. On smartphone cameras, the aperture is fixed, and the f-number varies from phone to phone. Some phones have a fixed aperture of f/2.0, others f/1.7 or even as low as f/1.4.
Why do smartphones have fixed aperture? Click here to find out.
5. Lenses and Focal Length
Realme X2 Pro (released October 2019) mobile camera specs
Measured in millimetres (mm), the term ‘focal length’ refers to the distance between the camera’s image sensor and where light converges and focuses the image inside the lens.
However, the measurement given in most smartphone camera specifications such as the one above show the 35mm full-frame equivalent and not the actual focal length of the smartphone’s camera, which is much smaller.
A lens’s focal length gives you an idea of its angle-of-view, as shown in brackets in the example above. A short focal length is great for shooting landscapes with your phone because it gives you a wide angle-of-view that captures more of the scene.
The longer the focal length of a lens is, the more magnified your subject will appear, and the less of the scene you’ll see in the frame. This is perfect for portrait photography, where the attention is on the person, not the scenery.
In a lot of cases, the rear cameras on smartphones with multiple cameras have lenses with different focal lengths. The focal length of the primary rear camera in the Realme X2 Pro example above is 26mm, which is typical of a wide-angle lens.
Larger focal lengths mean a reduced angle of view and more magnification, as is the case with the telephoto lens. In our X2 Pro example, the focal length of the telephoto is double that of the wide-angle lens at 52mm. This essentially means the Realme X2 Pro is capable of 2x OPTICAL zoom.
Ultrawide-angle lenses have an even wider angle of view than wide-angle lenses because they have a smaller focal length such as the 16mm ultrawide lens found on the X2 Pro.
In single-camera smartphones, the camera has a wide-angle lens. Dual-camera smartphones usually have a wide-angle lens and a telephoto lens but other combinations exist. The focal length and angle-of-view of these lenses differs from phone to phone according to the manufacturer.
The subject of focal length can be a bit tricky for some people to understand, so it’s difficult to explain it fully in just a few paragraphs. To understand focal length better and how it impacts your images, read this article.
Lens elements
Xiaomi Mi Note 10 (released November 2019) camera specs with a 7P primary camera lens
Some lens specifications like the one for the Xiaomi Mi Note 10 include a number like the “7P lens” spec above. This is an indication of how many lens elements are in that particular mobile camera’s lens array.
It is believed that more lens elements mean better picture quality. More on that here.
6. Auto-Focus
Vivo X30 5G (released December 2019) camera specs with PDAF and Laser AF
Auto-focus refers to the camera’s ability to bring the picture into sharp, clear focus on its own with little to no intervention from the user.
Currently, there are four ways in which auto-focus can be performed on a smartphone camera:
CDAF
With CDAF, the smartphone camera physically moves the lens back and forth until it detects the point at which the picture has more contrast and therefore is at its sharpest.
Although it does give good results, contrast-detection autofocus (CDAF) can be very slow and it doesn’t work that well in low light when the contrast in a scene is harder to detect.
PDAF
Phase detection auto-focus (PDAF) reserves roughly 10% or less of the pixels on a sensor and sets them aside to do nothing but collect data from the light waves entering the camera in order to set the focus.
These pixels are embedded with a phase-detection devices that convert light into an electric current called a photodiodes.
PDAF is considerably faster than CDAF at setting focus automatically.
Dual Pixel
Dual-pixel auto-focus is basically an improvement on phase detection autofocus. Where PDAF only has up to 10% of the photodiodes on the sensor enabled for phase detection, dual-pixel auto-focus uses 100% of them. This means accurate focus at lightning speed.
Laser Autofocus
With laser-autofocus, the phone shoots out an infrared beam towards the subject, and uses the time it takes for the light to bounce back to the camera to determine the distance to the subject. From there, the lens is moved to a position that will have the object in focus.
Laser autofocus is great in that it is very fast and can work just as well in low light conditions. However, the laser that the phone emits is rather weak (to avoid damage to the eyes) and doesn’t travel too far.
Some mobile cameras, such as the Vivo X30 5G camera pictured above, use more than one method of auto-focus.
If you’d like to learn more about mobile camera auto-focus and how it works, I recommend you check out my article on how smartphone cameras focus.
7. Image Stabilisation
OnePlus 8 (released April 2020) camera specifications with OIS and gyro-EIS
Image stabilization refers to the way a mobile camera reduces camera shake in order to avoid motion blur that is associated with camera movement while a photo is being taken. This contributes to the overall picture quality.
Image stabilization can be achieved mechanically (OIS), digitally (EIS), or through a combination of both (AIS).
Optical image stabilisation (OIS) counters slight movement and shake of the camera by moving the image sensor or the lenses using a gyroscope. This counter-movement helps reduce the amount of blur in your pictures introduced by unsteady handling.
Electronic image stabilisation (EIS) is more of a software-reliant post-processing effect rather than a mechanical function. And because of the way it works digitally, it is best suited for capturing stable video with a smartphone.
AIS is a stabilization system currently found on Huawei devices. AIS stands for Artificial Intelligence Stabilization and is mostly not any different from EIS.
To learn more about how image stabilisation works, particularly optical image stabilisation, click here.
8. Zoom
Camera specs for the Honor 30S 5G (released April 2020) with 3x optical zoom
For the longest time, smartphone cameras were only able to zoom in digitally. The problem is that digital zoom degrades the picture quality more and more the further you zoomed in.
Pixelation becomes an issue because, with digital zoom, the camera basically crops the image and then digitally expands it to fit the frame.
In an effort to improve picture quality when zooming in with a mobile camera, smartphone companies added optical zoom to their cameras when they introduced phones with multiple cameras.
Optical zoom is far better than digital zoom because it uses the lens to zoom, thus preserving picture quality. Unfortunately, phones with only one camera cannot zoom in optically.
Illustration of the difference in picture quality between digital zoom and optical zoom.
How far you can zoom in on your smartphone camera is determined by the focal length of the telephoto lens. As previously mentioned, on a multi-camera smartphone, you may find cameras with lenses that have different focal lengths that give your different angles-of-view.
If you take the focal length of the telephoto lens and divide it by the focal length of the wide-angle lens, it will give you the mobile camera’s advertised zoom range.
A lot of smartphone cameras with optical zoom commonly have 2x optical zoom because, typically, smartphone telephoto lenses have a focal length of around 50mm or so, and wide-angle lenses are generally around half of that.
Some phones, like the Honor 30S, have 3x optical zoom. That’s because the focal length of the telephoto lens is triple that of the wide-angle primary camera.
Digital zoom is actually one of the reasons why some smartphone manufacturers pack their cameras with a lot of megapixels. The more megapixels a camera has, the more the picture can be expanded and blown out digitally without worrying about pixelation. However, the picture quality will still deteriorate.
9. Periscope
Camera specs of the Huawei Nova 7 Pro (released April 2020) with 5x optical zoom
While on the topic of zoom, more and more high-end phone manufacturers are starting to include what’s known as a periscope camera in their smartphones, just like in the Huawei Nova 7 Pro example above.
A periscope camera is basically a camera system that is positioned sideways inside the body of the phone. So, instead of having the zoom lens array and the sensor lie parallel to the back of the phone, they’re perpendicular.
A prism or mirror system installed in the camera module reflects the light that enters the camera at an angle that passes the light through a group of lenses until it finally reaches the sensor.
How a periscope camera looks inside. Light is reflected by the prism and redirected to strike the sensor at an angle.
The periscope camera system is what allows the Nova 7 Pro to achieve 5x optical zoom without adding a big bulge to the back of the phone. Smartphone telephoto cameras without periscope zoom lenses generally only reach 2x or 3x optical zoom.
To zoom in further than this, smartphones rely on digital zoom, which, as I already mentioned several times, increasingly degrades the image as you zoom in. A smartphone periscope camera can zoom in further than a standard telephoto mobile camera lens can without heavily compromising the quality of the photo.
To learn more about periscope cameras, check out the article ‘What is A Smartphone Periscope Camera? And How Does It Work?
10. HDR
Camera specifications for the Asus ZenFone Max Pro M1 (released May 2018
HDR stands for High Dynamic Range. It allows you to capture images that have a great balance between the dark areas of the photo (known as shadows) and the lighter ones (highlights). This way, the resulting picture will neither be overexposed nor underexposed.
An underexposed image is combined with an overexposed one in order to create a high dynamic range (HDR) image. Source: www.bonusprint.co.uk
When HDR is enabled, the camera takes multiple pictures at different exposure levels. Then, with software technology, the photos are combined into the final composite photo with balanced highlights and shadows.
Auto-HDR means that the camera can analyse the scene on its own and determine whether it has very dark and very bright areas in the same shot. If it does, HDR will automatically be enabled when the photo is taken.
If a mobile camera’s specs show that it only has HDR and not auto-HDR, it basically means you will have to manually activate and deactivate HDR yourself whenever you want to use it for a shot.
Although using HDR can improve your mobile images, it does have its drawbacks. To learn how to use HDR on your smartphone camera, click here.
11. Flash
iPhone 11 (released September 2019) camera specs
There are different types of flash found on smartphone cameras, the most popular being LED. This type of flash uses small light-emitting diodes (LEDs) that give off light when a current is supplied to them. These LEDs are energy efficient and can provide continuous lighting.
Smartphone camera specs often specify how many LEDs a flash has. This can be a single LED, dual-LED, or even quad-LED, as is the case with the Apple iPhone 11 above.
Added to LED flash which has only one colour temperature, you get dual-tone LED flash which works by using LEDs of two different colour temperatures— warm and cool.
With dual-tone LED flash, the phone’s software figures out a balance between the “warm” LED and “cool” LED to give off a flash that better suits the ambient lighting of the environment.
Another type of flash that has made its rounds in the smartphone camera arena is the Xenon flash. Not many phones use this type of flash these days because, even though it’s a superior form of flash, it is rather expensive, power-consuming, and it doesn’t offer continuous lighting.
Using flash may seem like a good solution when shooting in low light but smartphone flash is nothing like professional flash photography. It can ruin a potentially good mobile photo and should be avoided as much as possible.
12. Panorama
Camera specs for the Motorola Moto G7 (released March 2019)
This basically refers to the camera’s ability to take multiple shots and stitch them together to create one blended super-wide shot.
The panorama mode can be accessed from within the camera app. To take the panorama, you’d need to frame up your first shot and then capture your panorama as you pan the smartphone from left to right or the other way around.
You can also take vertical panorama shots with your phone by tilting your camera up or down as you capture the shot.
Although you can get decent hand-held panorama shots, to get the best result, you’d need to use a tripod or a monopod.
13. Depth sensor
Camera specifications for the Meizu 17 (released May 2020) with a 0.3MP ToF depth sensor
A depth sensor is a camera that is solely responsible for analyzing the scene and creating a three-dimensional depth map from the data it has collected.
Depth maps are useful for things such as virtual reality and augmented reality applications. In mobile photography, depth maps are used to separate the foreground from the background in order to create the popular shallow depth-of-field bokeh effect, especially in portrait photos.
In most cases, depth cameras do not capture and save photos, they just provide depth data. As a result, these type of cameras usually don’t have a lot of megapixels. The Meizu 17 has a 0.3MP depth camera, which is very common.
There are different ways of creating a depth map and also different types of depth sensors. One type of depth sensor that is becoming increasingly popular is the ToF (Time-of-Flight) camera.
Almost like with Laser autofocus, the ToF camera uses infrared light to collect depth data. The time it takes for the light emitted from the camera to bounce back is measured and used to create a depth map.
14. Video resolution and frame rate
Video specs of the Vivo NEX 3S 5G (released March 2020) camera
Video resolution refers to the number of pixels that a video has in each dimension, similar to image resolution.
2160p= 4K
1080p= Full HD
720p= HD
The ‘@ xx fps’ refers to the frame rate of the video measured in ‘frames per second’ (fps). A typical movie has 24fps which essentially means in each second, there are 24 moving images displayed in succession.
The higher the frame rate, the smoother the video appears. 60fps is commonly used in smartphone cameras. Videos with low frame rates appear to lag and suffer from motion blur.
High frame rates such as 960fps are perfect for slow-mo video. With 960 images taken in one second, you can slow down the video quite a lot and still have crisp, fluid slow-motion action with little motion blur.
Dual video recording and dual video call
This means you can use both the front and rear cameras at the same time when recording video or when on a video call.
Conclusion
These are the commonly mentioned specs on smartphone camera spec sheets. It’s quite interesting that things like min/max shutter speed and ISO stops are not mentioned much anywhere because they play a big part in mobile photography.
Nonetheless, understanding all the specs discussed in this article will help you make a more informed decision when it comes to choosing the right phone with the right camera for you.
However, if you want to take good pictures with your phone, it takes a lot more than just knowing and understanding the camera specs. You need to understand how a mobile camera works and how to get the most out of it despite its limitations.
Why does it matter how your photos look? Because good photos are great for sharing online and in the real world with friends and family. Plus, if your mobile photos are really good, you can make some extra money by selling them online.
This article originally appeared in my other blog thesmartphonephotographer.com. Check it out!