A good camera in a smartphone is one of the biggest, if not the biggest, draw for most of the consumers. Smartphones companies have realized this and have started talking about the cameras in their phones to woo buyers.
But in the race to produce the perfect smartphone camera, different companies are taking a different approach. This means for consumers it is not possible to compare cameras in various phones on the basis of their specifications. The pixels that Lumia 1020 captures are different from those captured by Galaxy S5. Similarly, the pixels that iPhone 5S captures are different from those captured by HTC One.
So, what are these different approaches and which one is right? It is difficult to answer the second part of the question because it is too early to say which one is the best approach. But at the moment we can tell you a bit more about the cameras that different phones makers are putting in their phones.
Samsung: More megapixels approach
Over the years, most of the camera manufacturers have increased the amount of pixels that their devices can capture and have called that a progress. Most smartphone makers are also using the same approach. For example, Galaxy S, a flagship Samsung phone, came with a 5MP camera in 2010. In June this year, Galaxy S4 debuted with a 13MP camera.
This is not necessarily a bad approach. More pixels means a smartphone can capture more details and theoretically sharper images. But to get the best results, the camera has to be paired with the software that can properly utilize the pixels it is capturing and process the image in a better way. Companies like Sony are also pairing the high mega-pixel image sensor with better lenses. For example, the 20.7MP camera in Xperia Z1 comes with a G Lens, which is better than the typical lenses you will find on a smartphone.
Samsung is the prime example of what this traditional approach can do if the implementation is good. The company doesn't hype cameras in its flagship phones. But in terms of performance, they are some of the best shooters you can buy. Both Galaxy S3 and Galaxy S4 are capable of shooting detailed and sharp images and videos. The same is true for the cameras in Galaxy Note 3 and Galaxy Note 2.
HTC & Apple: The big pixel approach
One big weakness of traditional approach is low-light photography. More pixels on a small image sensor - there is not enough space to put big image sensors in a phone - means the pixel size is small. And as companies increase the number of pixels, it is getting smaller. This means in low light, there is likely to be lots of noise in images. There are two smartphone companies that are trying to tackle this problem by opting for bigger pixels - HTC and Apple.
With HTC One, the Taiwanese company introduced an image sensor that would take photos only in 4 mega pixels size. HTC argued that this size is big enough for photos that would be shared digitally or posted on social media websites. At the same time, low number of pixels allowed HTC to use bigger pixels - 2m - which could capture more light to aid a user in low-light photography. In comparison, the pixel size used by Galaxy 4 camera is 1.1 m.
Theoretically, HTC One should capture better images in low-light conditions and good images in proper light. But in actual use, HTC One camera falls a bit short, mostly because it can't capture enough detail with its 4MP camera. Yes, it does click better pictures in low light than most of the other smartphone cameras but overall it has an average camera compared to what you get with Galaxy S4 or iPhone 5.
With iPhone 5S Apple is following in the footsteps of HTC, but with caution. Apple increased the size of image sensor in iPhone 5S but without increasing the amount of pixels. iPhone 5S shoots images in 8MP just like iPhone 5 but the size of a pixel is bigger at 1.5 m. Apple believes this should provide the right balance between the amount of details and amount of light that iPhone 5S will capture. For now, it looks like Apple has the right balance.
Nokia: The oversampling approach
This is something totally unique and for now there is only one phone maker - Nokia -- that is using it. Nokia calls its camera technology PureView and it can be found in Nokia 808 and Lumia 1020.
The key to this technology is the 41 mega pixel image sensor that Nokia has created.
But contrary to popular perception, the images shot with Lumia 1020 are not produced in 41MP size. By default they are produced in 5MP size. But that doesn't mean Nokia is not making use of the 41 mega-pixel image sensor. The company says that it uses all the pixels its PureView camera can capture and processes them to create super pixels. This means noise and other imperfections within pixels are discarded. The 5MP image that you get is created using these super pixels that have tremendous amount of details. Nokia calls this process oversampling and says that not only it helps Lumia 1020 or Nokia 808 click better images in favourable conditions but also helps it keep amount of noise low in shooting conditions where light is poor.
The oversampling approach also allows PureView cameras to offer almost loseless zoom. This is a big draw in a smartphone camera where using high optical zoom is not feasible due to lack of space.
On paper this technology looks very good. And in practice it works very well, especially in adverse shooting conditions.
Motorola: The clear pixel approach
This is the approach Motorola is following. Traditionally, cameras use RGB (red, green, blue) sensor design. This method is also called Bayer Filter method. In simple words, the camera using this method captures pixels in green, blue and red. These pixels are then processed and a final image is produced.
In Moto X, Motorola using RGBC (red, green, blue, clear) filter on the image senor. Motorola claims that this improves low light photography by increasing the amount of light that image sensor captures. Theoretically this is true. But it is a tricky technology to use because even though it allows image sensor to capture more light, the filter also affects its ability to resolve colour properly. In practice, Moto X camera has produced disappointed results. Now the company has issued a software update and the camera performance in the device has improved but it still can't match the likes of Galaxy S4 or Lumia 1020.
Common factors
Other than working on different image sensor technologies, smartphone makers are also improving the design of lens in their cameras. Nokia, for example, started trend of optical image stabilization with Lumia 920 camera. Now the optical image stabilization can also be found in HTC One, Lumia 925, Lumia 1020 and LG G2. In theory, optical image stabilization should result in sharper images and videos. Similarly, companies are introducing lenses with wider openings. For example, the HTC One and Xperia Z1 lenses have an aperture of F2.0. The iPhone 5S camera has an aperture of F2.2. Theoretically lower aperture means better images in low-light conditions.
What is best for you
As we noted earlier, all approaches are theoretically good. But what matters is how well they have been implemented. For now, there is no clear winner, though PureView technology with oversampling offers best results, mostly due to the way Nokia has implemented it. But that said, camera in iPhone 5S, Galaxy S4 and Xperia Z1 are also very good and not too behind the camera in Lumia 1020 when it comes to producing quality pictures and videos.
