Flashback: Not only have smartphone camera sensors been bigger, they are getting smarter too

Flashback: Not only have smartphone camera sensors been bigger, they are getting smarter too

When it came to film photography, 35mm was by far the most popular choice, and it’s been used in anything from simple point-and-shoot cameras to expensive SLRs. It was so common that the focal length of lenses was still usually listed at the equivalent of 35mm. The digital transformation has brought “full-frame” DSLRs where the size of the sensors matches that of 35mm. However, it also brought in smaller digital cameras – small enough to fit in your pocket.

For them, the 1-inch sensor is the holy grail with cameras like the Sony RX100 series being a common example. They have stopped out of fashion as the capabilities of smartphone cameras have greatly improved, but they have had an impact on smartphones.

The Sony Xperia Pro-I borrowed the 1-inch sensor from its RX100 cousin, although it doesn’t have the optics to take full advantage of (it’s a 20-megapixel sensor, the Pro-I uses only 12-megapixels). We should note that the so-called 1″ sensors don’t measure 1″ in size, they are like 2/3″. Like the 35mm thing, this is another thing from older cameras.


The Sony Xperia Pro-I borrowed a 1-inch sensor from the RX100 line of premium cameras and photo cameras

Anyway, the Pro-I image sensor has an impressively large 2.4μm pixel—the 200MP ISOCELL HP3 we talked about last week only comes in at 2.24μm pixels with 16-in-1 binning. Of course, these two sensors are designed for two different cameras with two different use cases.

You probably know that the Pro-I isn’t the first smartphone with a 1-inch sensor, and it certainly won’t be the last – 2023 is expected to be the year when this type of sensor becomes the norm for a flagship.

Some of you may remember the Panasonic Lumix CM1 Smart Camera. The design of the case leaves no doubt that this is a camera phone packed with impressive brand hardware: a 20MP 1″ sensor behind a Leica f/2.8 lens and a “Venus Engine” that can record 1080p videos at 30fps ( and 4K at 15 frames per second).

The Lumix Smart Camera CM1 from Panasonic is an early example of a smartphone with a 1-inch sensor
The Lumix Smart Camera CM1 from Panasonic is an early example of a smartphone with a 1-inch sensor.

It was a chunky phone at 21mm thick and weighed 204g (well now, a lot for 2014). The CM1 runs Android 4.4 and the custom-designed camera app offers full manual controls.

Lumix CM1: Leica lens
Lumix CM1: Venus Video Engine
Lumix CM1: a physical control disc

Lumix CM1: Leica Lens • Venus Video Engine • Control Physical Disc

One really cool feature was that the silver ring around the lens was actually a dial that could be used to change the camera settings. The Lumix CM1 cost a whopping $1000, which at the time was considered pricey but not too bad for such a specialized set of equipment.

Let’s go back in time further. We talked a lot about the Nokia 808 PureView, a phone so advanced that it felt like it was from the future. When it came out in 2012, no other phone could really challenge it and its massive 1/1.2″ sensor. The Toshiba HES9 dwarfed the sensors of contemporary phones – here alongside the 1/3.2″ Sony IMX145 (8MP) that was used in the Galaxy S III of the same year.

1 / 1.2 Mega Sensor (Toshiba HES9) for Nokia 808 PureView
1/1.2″ Mega Sensor (Toshiba HES9) for Nokia 808 PureView

The PureView sensor has fairly large pixels even by modern standards, 1.4 μm, and a lot of them too – 41 megapixels. As we discussed last week, the first smartphone to outshine it in the precision game only came in 2018.

And it was precisely the high resolution that made the Nokia 808 feel so futuristic – the super-scanning technology used by default captured 8MP images and produced stunning every pixel quality and allowed for lossless digital zoom. Modern smartphones use a very similar approach, although there are some important differences.

By the way, if you are wondering how the Nokia 808 PureView compares to a modern smartphone, we tested it last year.

We compared it to the Xiaomi Mi 11 Ultra, the phone with the largest camera sensor of its day – Samsung’s ISOCELL GN2 was even larger than the 808’s sensor with a 1/1.12″ optical format (at 50MP which makes it 1.4μm pixels).

Xiaomi Mi 11 Ultra has packed a massive 1 / 1.12 ``` sensor, surpassing the 808 PureView (in more ways than one)
The Xiaomi Mi 11 Ultra has a huge 1/1.12-inch sensor, surpassing the 808 PureView (in more ways than one)

We want to take a little detour here and talk about pixels. When talking about digital cameras, you often see details about the aperture, sensor, and pixel sizes included. But not all pixels generate the same thing.

The 808 PureView’s sensor may have been impressively large and at a very high resolution, but it was old technology. It was a front-side illuminated (FSI) sensor, which means that the sensor circuits get in the way of the photodiodes. The Lumia 1020, Nokia’s next 41MP phone launched the following year, used a smaller (1/1.5 inch) back-illumination (BSI) sensor.

Front Side Lighting (FSI) vs. Back Side Lighting (BSI)
Front side lighting, also known as FSI vs. Back side lighting, aka BSI (image credit)

That’s not all, either. The name “ISOCELL” comes from the physical barriers that Isolation Individual pixels, which reduces crosstalk. Samsung has continued to develop the technology and touted many other advantages (such as a larger full well capacity, which measures the number of photons a pixel can collect before it reaches its maximum).

Transition from BSI to ISOCELL and the continuous development of ISOCELL
Transition from BSI to ISOCELL and the continuous development of ISOCELL

Samsung is not alone in this design, OmniVision, for example, has a similar technology called PureCel Plus:

OmniVision also optimizes pixels by isolating them from each other
OmniVision also optimizes pixels by isolating them from each other

OmniVision also optimizes pixels by isolating them from each other

There are other new developments, such as Sony’s stacked sensor design that separates the photodiodes and reads transistors into two separate layers rather than placing them side by side, increasing the surface area of ​​the photodiodes.

Sony develops stacked CMOS sensor design
Sony develops stacked CMOS sensor design

All this means is that pixel size alone is not the ultimate measure of image quality. In fact, such clever designs allowed sensor makers to shrink the pixel down to 0.56 µm (fun fact: the 1995 MHz Pentium Pro was built at 0.5 µm node and had 5.5 million transistors).

The successor to the Mi 11 Ultra is the Xiaomi 12S Ultra, which has switched up the difference and features a Sony IMX989 sensor for the main camera – an impressive 1-inch 50MP sensor. It’s much larger than the 1/1.5″ commonly found in phones today and even 1/1.3″ sensors. The Pixel 7 and iPhone 14 Pro fall into this category and have similar resolutions (and thus pixel size). The Galaxy S22 Ultra also has a 1 / 1.3 inch sensor (a hair smaller), but due to the 108 MP resolution, the physical pixels are smaller.

    1 inch Sony IMX989 for Xiaomi 12S Ultra
The latest in massive smartphone sensors: the 1-inch Sony IMX989 used in the Xiaomi 12S Ultra

But before the 12S Ultra there was another phone that used the IMX989 and that was the Sharp Aquos R6. It’s funny that the Aquos was also plastered with the Leica logo, which co-developed the camera with Sharp. So this is in common with Xiaomi. Sharp is responsible for many of the first things in the mobile phone industry, although the brand’s limited presence in the smartphone market means that these flagships often fly under the radar.

The Sharp Aquos R6 was actually the first with the IMX989 and its camera was co-developed with Leica as well.
The Sharp Aquos R6 was the first with the IMX989 and its camera was co-developed with Leica as well.

Rumors are circulating that several smartphone makers are working on flagships with 1-inch sensors, specifically one with medium resolution and large pixels. There will be quite a few models with 200MP cameras and smaller pixels as well. We can’t wait to see how the battle of the two philosophies unfold.

#Flashback #smartphone #camera #sensors #bigger #smarter

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