Why is the Samsung Note8’s camera ‘only’ 12MP when the Note 4’s was 16MP?

Why is the Samsung Note8’s camera ‘only’ 12MP when the Note 4’s was 16MP?

Updated 18/10/17: An earlier version of this article stated that the Note8 has a slightly larger sensor than the Note7. In fact, it was a slightly smaller one.

Megapixels matter. Sometimes. It’s all about context and constraints, something that Dr. Young Kwon Yoon, of the Advanced Camera R&D Group in Samsung’s Mobile Communications Business, understands thoroughly.

The Samsung Galaxy Note 4 was the first in the Note series to have a 16MP camera (the Note 3 had a 13MP camera), but the camera resolution was reduced to 12MP on the Note 7 (there was no Note 6). The Note8 is Samsung’s first smartphone with dual cameras, and both of them are the same 12MP, not 16MP. But why?

There’s a general perception that the more megapixels a camera has, the better its image quality. That’s true, up to a point — you’d rather have a 12MP camera than a 2MP one. The 12MP camera can capture more details than a 2MP one, as it has more pixels, or dots, to ‘draw’ an image with.

But sensor size also plays a part, and it constrains how many megapixels, or photosites, you can have on a surface area and still retain image quality. The more megapixels, the smaller the individual photosite that represents a pixel, and the less light it can capture.

That’s why a camera like the Sony Alpha 7S II, for example, caps its resolution at 12MP, while the Sony Alpha 7R II shoots at 42.4MP. Both have the same, full-frame sized sensor, but the 7S II is renowned for low-light performance, because its larger-sized photosites can capture more light.

At a recent visit to Samsung Mobile’s headquarters in Suwon, South Korea, Dr. Yoon explained why the latest Notes have fewer megapixels compared to earlier ones: “The megapixel is just one of the factors that influence the picture quality of cameras. There are so many different elements that influence the satisfaction level of the pictures. Depending on the consumption patterns of the pictures, different elements may become more important or less important.

“If you have higher megapixels, that’s more advantageous for printing, or for large displays. However, that also means the sensor pixel size goes down, which results in lower resolution and lower color rendering.”

12MP might sound like a small number, but a good 12MP image is enough to print an A4 image at 300ppi. It’s doubtful that many smartphone users would print photographs even at that size, so 12MP is ‘good enough’ for most.

The Note 5, which was the last Note to have a 16MP sensor, had a sensor that measured 1/2.6” and had a pixel size of 1.12 μm. In contrast, the Note 7 had a smaller megapixel count of 12MP and only a slightly larger sensor that measured 1/2.5”, but it had larger 1.4 μm pixels. The Note8 decreases the wide-angle camera sensor slightly, at 1/2.55”, with a pixel size of 1.4 μm. It should be noted, however, that the telephoto camera has a smaller sensor that measures 1/3.6”, with a pixel size of 1.0 μm.

The overall increase in sensor size, while dropping and then maintaining the megapixel count at 12MP, shows how Samsung believes that other factors like low light performance are more important to pure resolution.

“The smartphone user trend is shifting to on-device taking of the pictures and actually increasing the individual pixel size is useful for the picture quality,” Dr. Yoon continued.

“Currently most of the smartphone users create pictures on-device, consume pictures on-device and also share the pictures on-device. So we believe that the usability and Dual Pixel sensor is more tailored to the current trend rather than the megapixel resolution.”