In this buying guide article we’ll take a look at the key features, specs and all the important things you should know about the phone’s camera. This online guide will give you a clear understanding of the things that are useful to understand, in order to make sure that you are picking the camera phone that is best for your needs.
A Camera Phone as a Main Camera
Many people are now using their mobile phone camera as their main camera. The reason is simple, because it’s already there in your phone, so why not user. The main advantage of having a high-quality camera is that you can use it in your everyday life. It’s there in your pocket, and you can take it out and capture a shot no matter where you are.
Furthermore, mobile phone cameras enjoy one of the best features that any camera can have, which is a constant wireless/Internet connectivity and the access to a broad selection of photo editing, camera capture and social image sharing related apps. This makes the mobile phone camera a very friendly and useful tool for capturing and sharing previous moments.
There are some caveats though. Most of the camera in mobile phone and tablet devices still lack an optical zoom and have small image sensors. Having said that, for the average photographer, it’s better to have a camera in your pocket, than not having one. I have a DSLR camera, but I certainly not going to carry a specific bag for it and carry it everywhere I go.
The image quality of mobile phone cameras is continuously improving in each generation. We ca see some mobile phone cameras with larger sensors and faster aperture lenses that allows you to take gorgeous photos, even in low-light situations.
The best part of using a mobile phone camera is that it’s very easy to instantly share your photos and videos with your friends and colleagues via social networks like Twitter, Facebook, Instagram and others. Toucscreen operation on a large screen makes it very easy to compose your shot and operate the camera. Many of the latest phones are already equipped a rear camera and a front camera for taking high-quality selfies. It seems that for many people there is no need to carry a secondary camera, even if it has an optical zoom.
Many people still find superzoom digital cameras to be the best choice when traveling abroad. The fact that you can zoom in on far away subjects makes it easier to come home with more unique and exclusive photos. It really depends on what you are searching for in a camera: do you want it to be water-resistant?, do you need an optical zoom?, do you need manual controls?, etc.
In this buying guide I’ll try to help you focus on the features that help you pick up the camera that best fits your needs. To start, you need to understand the basic concepts related to digital cameras, and most of them aren’t mobile-specific, but are common between all digital cameras, mobile and conventional.
The Camera Sensor
The camera image sensor is probably the most talked about among all the camera features. In the past you probably wouldn’t have payed attention to it, but many phone manufactures started to give attention to it in their marketing campaigns.
In general, you want to have the camera with the largest sensor, and to be more specific, a camera with the largest pixels. The larger the pixels, the more color information each pixel can capture. This information is obtained from the photons of light. For get the best low-light performance, it’s better to search for a camera that has a back-illuminated sensor and relatively large pixels. BSI currently the leading technology in image sensors, and it improved the light gathering capability (sensitivity) of the sensor to light. Most of the mobile phones today use this technology, although we already see some next-gen front-illuminated implementations, that improve over the conventional FSI sensor.
The pixels are measured in microns. For example, the Sony Xperia Z5 rear facing camera has a 1/2.3″ 23-megapixel resolution Exmor RS image sensor. This sensor uses a stacked-sensor technology, that improved over the traditional BSI technology by creating a better separation between the photosensitive part and the electronics part. This new generation sensors include ob-board memory which is placed close to the image acquisition electronics, allowing faster and more efficient readouts of the color data for each pixels.
The Xperia Z5 camera can produce image up to 5,520 x 4,140 pixels (22.85MP). But because the resolution is so high, each pixel is around 1.1 micron in size. Which is relatively small, even in mobile phone camera terms. Sony probably wouldn’t had gone for such a high resolution with a smaller sensor. 1/2.3″ is a relatively large sensor in mobile sensor terms.
Here are some sensor sizes relative to each other.
What to looks for: preferably large sensor, large pixels, BSI or Stacked Sensor technology. This will ensure that the camera cam capture high-quality images, has good low-light performance and get produce better shallow depth of field effect (the sensor size/focal length and the lens aperture have a direct effect on the depth of field).
The lens aperture is the hole through which the light passes through the lens to the camera image sensor. The aperture value or values is written like this:
It can be written with the forward slash or without it and with a capital ‘F’ or in lowercase. The smaller the f-number, the higher the lens pupil is and the higher the amount of light that can pass through it. This means that you should prefer a camera that has a smaller aperture value. So f/1.4 is better than f/1.8.
You can use this stops calculator to calculate the different in stops between two apertures. The differences is measured in stops. 1 stop equals double the amount of light. Two stops means (2*2) 4 times the light. 3-stops means (2*2*2) 8 times more light, and so on.
Let’s compare some aperture from some popular mobile phone cameras:
- f/1.8 – LG G4
- f/1.9 – Samsung Galaxy Note 5
- f/2.0 – Motorola Moto X Style
- f/2.2 – Apple iPhone 6 Plus
As you can see from the above list, the LG G4 rear camera has the fastest aperture among the other phone cameras. It has the lowest f-number of F1.8. If we compare the LG G4 aperture to the iPhone 6 Plus f/2.2 aperture using the website I linked above, we get that the LG G4 f/1.8 aperture is 0.579 stops faster than f/2.2 of the iPhone 6 Plus, and it allows approximately 1.5x times more light.
The best low-light cameras on the market usually have a relatively very low f-number below f/2.0. There are two times of lenses, prime and zoom lenses. A prime lens has no zoom, or actually have a 1x zoom to be exact. This is why you see only a single f-number. In zoom lenses you are going to see an f-number range, something like f/2.8-f/4.0. So in this particular example, the first f-number tells us the aperture when shooting at the widest angle (lowest zoom), and the second aperture number tells us the aperture when shooting with the narrowest angle (largest zoom).
In mobile phone cameras with prime lenses (single focal length lenses), the aperture is fixed and doesn’t change.
A lower f-number, for the same given sensor size, will produce a more prominent defocused background blur effect. Another thing to consider, but keep in mind that there are some apps that allows you to mimick this shallow depth of field effect. Among the popular apps are Big Lens, Bokeh SOOC (Straight our of camera) and Google’s new Lens Blur mode among others.
What to looks for: a camera with a brighter lens, one with a lower f-number (larger aperture opening).
Lens Focal Length
The lens focal length is measured in millimeters and measured the distance between the lens first element and the sensor. Most phone manufacturers will tell us the equivalent focal length in mm in 35mm terms. This is actually the number you should be looking for, because it can be easily translated to the angle field of view.
For example: The Galaxy Note 5 has a 4.30mm lens, and it’s equivalent to 28mm in a full frame camera. The iPhone 6 Plus has a 4.15mm focal length, which is also equal to 28mm. The reason that the two lenses have the same equivalent focal length even with different default values, is because they have different sensor sizes. This is why it’s important to search for the 35mm equivalent value and not the actual non-equivalent one. It help us compare the two values and know the difference between the angle of view the captured frame.
Now, a large focal length number means narrower field of view. A smaller focal length means wider field of view. A wider field of view is useful for selfies, landscape and interiors, because you can fit more of the subject and its surroundings into the frame. This is why front-facing selfie cameras have a smaller aperture, a wider field of view.
You can use this website to calculate the Angular Field of View from a given lens focal length, focal length multiplier and the image ratio of the sensor. It will give you the horizontal, vertical and diagonal FOV.
Also keep in mind that prime lenses (those without zoom), will have a single focal length number. Zoom lenses will have two focal length numbers. Here’s an example:
- Asus Zenfone Zoom: 28-84mm (35mm equivalent) f/2.7-4.8 lens
- LG G4: 29mm (35mm equivalent) f/1.8 lens
- Samsung Galaxy S6 edge: 28mm (35mm equivalent) f/1.9 lens
The Asus Zenfone Zoom is a smartphone with a 3x optical zoom. By the way, the optical zoom is calculated by dividing the second focal length number to the first one. So in the Asus Zenfone Zoom case, 84 / 28 = 3 optical zoom. This is why the S6 edge has 28 / 28 = 1 optical zoom (single focal length, so 1x zoom). Furthermore, for a given sensor size and same aperture, a camera with the largest focal length will result in a shallower depth of field effect, because it creates a less compressed background effect.
What to looks for: a smaller focal length is better for selfies and when shooting in tight places. Variable focal length (zoom lens) is more versatile as you can change zoom on the fly and get closer to the subject.
Low Light Performance
‘Low Light Performance’ hides a lot of things underneath it. If you find yourself shooting a lot in low-light, you certainly want to make sure that you buy a phone with good low-light capabilities.
As I mentioned before, make sure that the camera uses a back-illuminated sensor and has large pixels. Second, make sure that it has a fast aperture (lower f-number), which will allow more light to pass through the lens. The lens aperture is probably among the most important ones, so make sure you don’t skip it.
Third, make sure that you have a rear flash unit at the back (or even rear). Xenon flashes provided stronger illumination than LED lights, but a LED flash can give constant illumination when shooting videos. A flash is very useful when shooting indoors, because the light bounces from the walls and helps illuminate both the room and the subject, but it’s also useful when shooting outdoors, as long as the subject is close to the camera.
When I look for the best low-light mobile phone camera, I am not only looking at the dry specs, but also search for side by side high ISO sample images or at least view some high ISO sample images online.
The high ISO performance tells us about the image quality when shooting in high sensor sensitivities. A camera can have a very fast aperture and latest generation sensor, but in some cases it’snot enough. This is why the camera allows you to bump up the ISO sensitivity to be able to get a well exposed image. Higher ISO also means more image noise, which at higher ISO settings, can make the image to become very noisy and even not usable. Some phones allow you to manually adjust the ISO value, others do that automatically for you.
Both gsmarena.com and phonearena.com have their photo compare tool that allows you to observe the differences between two cameras, but lack the option to see how all perform in different ISO sensitivities. For that you should use Google to search for versus comparison that will show you exactly how two or more cameras perform side by side in different ISO sensitivities.
Another very important feature is the optical image stabilization mechanism. This mechanism helps to prevent blurry images when shooting handheld with shutter speeds under the recommended one (recommended shutter speed: > 1/focal length). So for example, if you shoot with a 28mm lens, you should be shooting with a minimum 1/28 sec shutter speed to get a sharp image. Shooting at a slower shutter speed can result in a blurry image. An optical image stabilization allows you to choose with even slower shutter speeds, allowing more light to pass through, but still get a sharp image.
OIS effectiveness is measured in f-stops. Search if you can find the EV compensation value. For example, a 4EV compensation OIS means that the camera can shoot at shutter speeds 4-stops lower than the recommended and you still achieve sharp results. So if you shoot at 60mm, you need to set the shutter speed to be at least 1/60s. With an OIS with 4EV compensation, you can shoot at 1/4 of a second and get a sharp image. It’s very useful for stills, but the OIS is also useful for stabilizing videos.
There is also a digital image stabilization, which unlike the optical one, it’s useful mainly for videos.
What to looks for: compare high ISO sample images, go with an optical image stabilization and choose a camera with a broader ISO sensitivity range and preferably one that you can manually adjust the ISO yourself.
Other Important Features
It’s important to learn and understand the camera specs, but there are other features that are also very important, this includes among others:
- Large and high-resolution display: easy to compose and edit your images and videos
- CPU Performance: faster camera operation, image and video editing
- Battery Life: you don’t want to hand around with a second battery I assume. Make sure that your phone has a good battery life. Large phones have larger batteries and better battery life overall
- Make sure it has a front-facing camera, so you can take selfies
- Check what camera apps are built-in. Some of those apps are tightly related to the phone design and hardware, which can give you unique features that some other apps won’t offer, at least not if the phone was just announced and devs haven’t developed apps for the new hardware
- Make sure you have a large built-in storage space, or the phone have a memory card slot. This is especially important if you intend to shoot a lot and capture high-quality 4K or Full HD videos at high frame rates
- Check the burst speed, the maximum frames per second the camera can capture images in a sequence
- The camera specs are different for the rear and front camera, so make sure you look at them both
Don’t forget to skip the video features. Some smartphones come with 4K UHD video recording option, that look amazing on a 4K display. There are tons of apps for video editing that will convince even those who don’t like shooting videos, to start shooting ones. You want your memories to be crisp and clear, so your kids can see how you lived when they grow up (just imagine it, who have thought about it a 20 years ago). I wish I had the option to view videos of my grandparents parents, this would be an amazing experience. Now you have the option to save those memories and let the next generation see how you lived and pass those memories for next generations.
I share with you some of the key features and important things you should know before buying a new phone or tablet device. I always pay a great deal of attention to the camera features when buying a new phone. There are so many camera apps out there that makes using the camera such a great joy. Don’t overlook it, and make sure you pick up the camera that best fit your needs.