Why Your Smartphone Needs More Than Just Megapixels 2021


Key Takeaways

The Xiaomi Mi 11 has a whopping 108 megapixel sensor in its main camera.Even its screen has better specs than high-end computer monitors—on paper.The downsides of so many pixels outweigh the advantages. Xiaomi

Xiaomi's new Mi 11 smartphone packs a ridiculous 108 megapixels onto its tiny camera sensor, which is more than Fujifilm's new $6,000 GFX100S. But why? One thing's for sure. It won't make the images any better. 

The Mi 11 smartphone, available for the first time outside China, seems designed only to show off some absurdly over-provisioned specifications, including the camera. But what's the point? You can make big prints from such a sensor, but who prints photos any more anyway? And aren't there downsides to using such a dense sensor in a phone?

"There is no actual reason for a phone to have a 108MP camera," real-estate photographer Matthew Digati told Ach5 via email.

"In my professional work, I use a camera with 24MP. The only reason you would ever need a 108MP camera would be if you are planning on producing huge prints. And I really mean HUGE prints, like the size of a building."

Trying Too Hard

If you were making lists of specifications, then the Mi 11 would top all of them. The 6.81-inch AMOLED screen has a 120Hz refresh rate (double that of the iPhone 12), with a 3,200 x 1,440 resolution. The display supports 10-bit color, which is usually only found in high-quality computer monitors.

"There are multiple challenges in packing that many megapixels into such a small sensor."

It's also bright, with a maximum light output of 1,500 nits. For context, Apple's $6,000 Pro Display XDR has a peak brightness output of 1,600 nits.

But then we get to the cameras. The selfie camera alone packs 20MP, the ultra-wide has 13MP, and the telephoto has a mere 5MP. But the main event is the primary camera, which uses an absurd 108MP. But why is that bad?

How Much?

Below is a video from photographer and educator Kevin Raposo that compares the 108-megapixel camera in Samsung's Galaxy S21 Ultra with a professional DSLR. 

There are some advantages to a high pixel count. One we mentioned already—the ability to make large prints.

Another is "downsampling," where the information from several adjacent pixels is compared and combined to make a smaller, but cleaner image. This is usually what high-megapixel phones do. It also lets you crop images, and still have a picture that looks good on Instagram.

But the sensors in cameras are tiny, and packing on all those pixels has a cost.

"Not only is a 108MP camera unnecessary in general, but it comes with some major drawbacks as well," says Digati. "The amount of memory and processing power needed to capture and store a 108MP photo is enormous."

"There are multiple challenges in packing that many megapixels into such a small sensor," photographer Niklas Rasmussen told Ach5 via email. "Because of the sensor size, every pixel has to be very small. That makes them far less light sensitive, which could introduce more noise into the image."

What's more, most of the advantages of a high pixel count could be realized just as well with a much lower number. Even having the main camera's sensor at "just" 54MP would still allow downsampling, cropping, and the making of large prints.


If you watch Raposo's video, above, then you'll notice something else. Shown on a screen, the Canon 1DX MkII images aren't much better than those from the Galaxy S21 Ultra. Shown larger, on a giant monitor or printed, the Canon images win easily.

But at the sizes we usually view images—on phone and tablet screens—the Galaxy is good enough. That's not down to the extra pixels, though. The iPhone makes great-looking images, for example, with its 12MP camera. 


What this comes down to, then, is marketing. In a market where all Android phones are pretty similar, especially to the non-informed or non-enthusiast buyer, throwing out huge numbers like this is a great way to differentiate your products. Unfortunately, it's not a great way to build a better camera.