QuickCheck: Should megapixel envy be a thing?

WITH smartphone brands competing over having the best camera, does measuring it by megapixels really make sense?

Are megapixels the only thing to consider when choosing a smartphone camera?

Verdict:

FALSE

One of the most touted features for smartphones is usually the camera quality.

Marketing leads us to believe the easiest way to measure this quality is by counting how many megapixels (MP) it has. In fact this trend has persisted for years: first generation smartphones had 2MP cameras, now high end smartphones can have cameras with as high as 108MP.

However, bigger numbers alone might not be a true measure of quality.

Firstly, a megapixel just refers to one million pixels. These pixels are the tiny receptors on an image sensor, a computer chip in digital cameras that captures light and translates into a digital image.

In theory, more pixels should enable these image sensors to capture more details and create a sharper image.

But in practical terms, the size of the image sensor matters more since it enables the system to capture more light - which is essentially the raw data from the real world.

A big image sensor will capture more data, then its many megapixels will help record that data accurately. Even with the same number of megapixels, a small image sensor will capture less data.

Another problem of squishing so many pixels on a smaller space is that they can create electronic noise which muddles the information they try to record, leading to artefacts - things that look like grey grains or discolouration.

So how big are image sensors on smartphones versus a full-frame DSLR camera? Recent smartphones have sensors ranging from 1/1.25 inches to 1/1.7 inches in size, while full-frame DSLRs use a standard 35mm sensor.

Translating these different measuring conventions into a similar size - in mm squared - smartphone cameras sensors are between 25mm² to 43mm², while a full-frame sensor is 864mm². That’s between 20-30 times larger!

And yet these large pro cameras still have about 20-40MP only, while some brands like Sony even have models that boast having fewer megapixels to reduce artefacts and noise.

There are advantages with having more megapixels though, you can display these images at larger sizes thanks to having more fine detail captured. This means you can digitally zoom in or crop the image, while potentially maintaining high image quality.

Photography community site Fstoppers did a test between a camera with 12MP and 24MP and found the one with fewer megapixels did produce slightly less detailed photos. But only when printed out as a 40x60” photo, roughly the size of a flat screen TV.

Some may argue that they do want to show their photos and videos on the TV, and in that case the extra cost for higher megapixel devices with a larger image sensor might be worth it to them.

On a smartphone screen or shared over social media, there is little appreciable difference. The images would either be too small on a 5" screen, or end up compressed by the website to save bandwidth.

Conversely, in a digital only space, another benefit of having fewer pixels is the resulting image has a smaller file size.

For smartphones with limited space or when sharing original size files with friends, this could translate to a significant savings in terms of buying a phone with more onboard memory and how much mobile internet data you use.

References:

1. https://fstoppers.com/gear/12-megapixels-enough-sony-a7s-iii-print-comparison-562360