How Many Megapixels Do I Actually Need? – KobraTech
How Many Megapixels Do I Actually Need?

How Many Megapixels Do I Actually Need?

The amount of megapixels required on a smartphone is not a set number. This issue sadly doesn’t have a clear answer and the debate gets technical very quickly.  Checking the number of megapixels that a phone has before buying it is certainly a good indicator. It can show you how good the photos will turn out. To an extent. However, to capture a photo with the highest-quality depends on many factors. It doesn’t just rely on the number of megapixels that the phone has. In fact, the number of megapixels means nothing if the other features aren’t also up to scratch.

Huh?

In order to understand this dilemma, it is important to have the basic knowledge of pixels. Without getting too physicsy, I will try to explain what they are and how they work. One megapixel is one million pixels. These pixels are tiny squares of information. They capture the light through the lens and turn the light into data. Simple. If a camera has a resolution of 8MP, this means it captures images with eight million squares of information per inch.

Size or sensor?

With this description you may come to the conclusion that therefore the greater number of pixels, the better. Yet this is a common misconception. Phone manufacturas use the number of MPs as a marketing ploy. Within the industry, phone models compete due to the amount of megapixels they have. And of course, people think the bigger the better. Yet this is not true.

There are two issues here. Firstly, pixels are a measure of quantity and not quality. The higher the number of pixels doesn’t guarantee a better photo. In contrast, it’s how big each pixel is and not how many there are which is important. A good analogy commonly used to explain how pixels collect light (photons) is with a bucket and raindrops. Pixels need to collect as much information or water as possible. To do this, a bigger bucket is better. It’s about the balance between pixel size and amount of them.

Secondly, what we really need to focus on when it comes to pixels is the image sensor. This is essentially where the pixels live. The larger the image sensor means the larger the individual pixels are. Larger pixels can collect more photons. The outcome is a cleaner picture with less disruption and higher resolution. The sensor determines how much light can be let in and this is what is most important. 8-megapixel cameras are pretty common. However, your DSLR with 8MPs will produce a better image than your smartphone because it has a larger image sensor.

Image sensors vary in sizes and are measured in inches. A sensor can be the size of a small aspirin pill or as big as a fingernail. They range roughly between 1’’ to 1/3.2’’. The smaller the number the better. The sensors are considerably smaller in smartphones due to their physical limitations. These are usually at around 1/2.3’’ to 1/3’’. For example, an iPhone is thought to have a 1/3’’ sensor although like most other manufacturers, Apple tries to keep this information hidden.

For smartphones, the size of the individual pixels, measured in microns, has increased in recent years. Now they can be a similar size to the pixels used in a point and shoot camera. This makes the drawback of a smaller sensor less of an issue than it was before. Yet there is always room for more improvement, and companies are relentlessly researching to develop further.

Can I have too many pixels?

Maybe you’re still convinced that more megapixels means better photos. However, it can also go the other way. Too many pixels can be a burden. Let’s get slightly technical again. The information that pixels capture isn’t entirely ‘good’ information. The data comes out as good and bad. This bad data is visible through the grainy aspects of a photo or noise as it’s known. Therefore, if the number of pixels on a smartphone is big, it means the pixels are smaller. If each pixel is smaller then they let in a greater amount of noise.

Another drawback of too many pixels is about storage. Too many means the photo takes up more space because has a greater amount of data. This also leads to longer and slower uploads and more memory consumption. If there is an excess of pixels then the image will be compressed. Random pixels are deleted at this stage which can be damaging to the image. There is certainly advancement when it comes to processing photos with a smartphone. However a balance must be struck between resolution and data size.

So the answer please?

There is a time when an abundance of pixels can be a good thing. It works if you either want to crop your image a lot, or blow it up and print it large. 300 pixels per inch (ppi) is recognised as around the sharpest the eye can observe. Therefore if you times 300 with the width and length you require for you print, you get the number of pixels needed to create the best quality image.

However, these days we mostly view and share our photos via a computer or phone screen. And this we often do on platforms such as Facebook. For that, the number of pixels required is considerably lower. You need around 128x128 pixels for a Facebook profile picture when seen on a smartphone.

Convinced? As megapixels aren’t everything, it is important to consider other factors such as the size of the image sensor. This can be hard however when the majority of companies conceal this information, perhaps due to its limitations.

Others factors to take into account include the aperture, the lens itself and what editing software you choose to use. Some photographers argue that no one needs a camera with more than 8MPs. Yet perhaps this will change in a few years and the norm will become 20MPs. Current smartphone releases are boasting cameras with 12MPs, even up to 20MPs. But remember, everything in proportion is important. As long as you keep a balance between all the different elements, you should produce a photo you’ll proud of.