Xiaomi Redmi Note 8 Pro, 64 MP Samsung ISOCELL Plus sensor

Navigation

  1. How did it start?
  2. History
  3. Evolution of ISOCELL Plus
  4. Tetracell
  5. Tetra HDR
  6. Other sensor properties
  7. ISOCELL Plus GW1 sensor on other phones
  8. 4 more cameras
  9. Image quality and sample photos
  10. My experience
  11. User Comments
  12. Add your review or question on the lens

How did it start?

Phone / smartphone / camera phone / game phone Xiaomi Redmi Note 8 Pro 6 / 128GB belongs to my mother, who has been active lately maintains his blog on Instagram... She changed her old phone ZTE NUBIA M2 4/64 on new Xiaomi Redmi Note 8 Pro 6 / 128GB due to the insufficient quality of the first images. The phone was purchased at Power outlet here here.

By the way, pictures from ZTE NUBIA M2 4/64 with the main sensor Sony IMX258 13 MP were in my note “What is filmed for".

With a general smartphone concept Xiaomi Redmi Note 8 Pro 6 / 128GB you can read in this video:

 

Main camera Xiaomi Redmi Note 8 Pro 6 / 128GB on 64 MP uses sensor SAMSUNG CMOS BSI Bright ISOCELL Plus GW1 (S5KGW1) with BSI, Tetracell, DCG and Tetra HDR technologies. It seemed to me very funny the presence of 64 MP in an inexpensive smartphone and I decided to figure out what and how it really is.

History

Samsung's ISOCELL Plus GW1 sensor was announced in May 2019. Already August 29 2019 an inexpensive smartphone was introduced Redmire Xiaomi Note Pro 8... On September 13, 2019, another smartphone was announced using this sensor - it became Realme XT, but due to the fact that the official teasers from Realme XT earlier, it is believed that exactly Realme XT became the first camera phone with a 64 MP sensor. Anyway, Realme XT и Redmire Xiaomi Note Pro 8 are pioneers with sensors above the psychological mark by 50 MP.

SAMSUNG CMOS BSI Bright ISOCELL Plus GW1

SAMSUNG CMOS BSI Bright ISOCELL Plus GW1

ISOCELL Plus

ISOCELL technology (Isolated single Cell - isolation of cells / pixels) was introduced in 2013 and is still developing. ISOCELL has undergone several major updates: BSI -> ISOCELL -> ISOCELL PLUS.

ISOCELL

Evolution of ISOCELL technology. Conventional ISOCELL technology isolates adjacent cells / pixels from signal loss with metal barriers. The updated ISOCELL Plus technology makes it even better, using a new material (not metal), which allows for a better signal by 10-15%.

Tetracell

In short, thanks to Tetracell technology, information from four adjacent subpixels (photodiodes) of the same color can be combined (called 'binning'), which ultimately leads to an increase in the physical size of the subpixel, and this allows you to absorb more light and give less noise when shooting with poor lighting. With this combination, a 16 MP image is obtained (64/4 = 16).

The result is a very interesting situation: when there is a lot of light - you can get high details of the picture using the sensor in 64 MP mode, when there is little light - you can sacrifice the resolution, but reduce the noise level by combining the subpixels.

In addition, the four subpixels, arranged in a 2 X 2 square, are covered with a single color bayer filter, which simplifies the production of such a sensor. For 64 MP, only 16 million color filters are needed.

TetraCell

TetraCell. One of the key features is that four subpixels (tetra-block) are covered with one color bayer filter. This simplifies production. And because of this, these four subpixels can be combined by the algorithm into one large one, which allows you to lower the image resolution, and with it, reduce the noise level.

When a sensor based on Tetracell technology operates in binning mode, it does not fundamentally differ from Bayer RGB by its mosaic pattern. It's just that 4 subpixels of the same color become one big one, but the 'large merged subpixels' pattern itself is completely analogous to the classic Bayer RGB pattern.

TetraCell. One of the key features

TetraCell. Subpixel mosaic.

When a sensor based on Tetracell technology works in the usual mode (without combining), then you have to make a specialized demosaicing algorithm. In classic RGB, each blue and red pixel is adjacent to four green pixels. In TetraCell, each blue and red sub-pixel is adjacent to two green and two pixels of its own color. In general, classic RGB should produce a better color quality than TetraCell. Specific demosaic for restoring the color of the final image is a disadvantage of TetraCell technology.

TetraCell

TetraCell. An analogy for demosaicing.

Tetracell technology is similar to Sony's Quad Bayer.

Later on, Tetracell technology was supplemented with a similar technology. Nonacell (which can be found on phones Samsung Galaxy S20 Ultra).

Tetra HDR

Tetracell allows you to take HDR images in one pass. In HDR mode, the subpixels in the tetra-blocks operate at different times (at different shutter speeds), which allows you to create a braking effect and expand the dynamic range of the image. In this case, you do not need to take two pictures in a row and glue them together. But, unfortunately, when working in this mode, you can only get 16 MP images.

TetraCell

TetraCell. Subpixels work on Long (L) and Short (K) shutter speed, which allows you to get HDR in one conditional cycle (conditionally, two images are superimposed with different exposures due to different shutter speeds at which the subpixels operate, which allows you to expand the dynamic range of the image).

Physical dimensions of the sensor

Physical size of the main sensor 1 / 1.72 in.... The diagonal is 9.216 mm, width 7.6 mm, height 5.7 mm, which gives us crop factor Kf = 4.55... The sensor area is approximately 20 times smaller than the classic Full Frame 36 mm X 24 mm sensor. Pixel size 0,8 microns (one of the smallest pixel sizes for 2019-2020).

If the full-frame sensor of a modern full-frame camera is filled with pixels of the same size as the main module Redmire Xiaomi Note Pro 8, then we would get at the output 1276 megapixel! It is easy to count: (36 * 24) / (7,6 * 5,7) * 64 = 1276 (MP).

The maximum image size is 9248 X 6936 pixels. Almost 10.000 pixels on the long side! Frame aspect ratio 4:3 (not the classic 3: 2 on many digital cameras).

Used optics with F / 1.89 и 5.43 mm focal length with a viewing angle of 79 degrees (diagonal). In terms of Full Frame, we get an EGF equal to about 26 mm focal length.

Other properties of the sensor:

  • to focus using phase sensors Super-PD (PDAF) + contrast focusing
  • there is an opportunity to shoot 4K video with frame size 3840 X 2160 and 30 fps
  • Full HD 60 fps
  • it is possible to shoot slow motion HD video with a frequency 960 fps
  • the burst speed of the main module for photo is maximum 21 fps
  • sensor uses 10-bit ADC
  • range ISO-100 3200
  • Minimal excerpt is 1 / 16.000 seconds
  • the average weight of 64 MP is 10-20 MB, the maximum size of the created JPEG file that I have seen was more than 30 MB
  • no optical stabilization
SAMSUNG CMOS BSI Bright ISOCELL Plus GW1

SAMSUNG CMOS BSI Bright ISOCELL Plus GW1

ISOCELL Plus GW1 sensor on other phones:

The same 64 MP sensor is used in other models:

But in Samsung Galaxy S20 и Samsung Galaxy S20 Plus a second generation SAMSUNG CMOS Bright ISOCELL Plus GW2 (S5KGW2) sensor with regular RGB instead of TetraCell is used.

4 more cameras:

Xiaomi Redmi Note 8 Pro 6 / 128GB has 4 more cameras:

  • For macro photography, with a focusing distance of 2 centimeters, 2 MP, shoots poorly even by phone standards
  • Wide-angle, with a viewing angle of 120 degrees diagonally, 8 MP with an aperture of f / 2.2, shoots quite passably, but the corners and edges are very weak
  • 2 MP depth-of-field camera (it does not create an image itself, but helps when shooting with a blurred background)
  • Front selfie camera at 20 MP with f / 2.0, shoots quite passably

Image quality and sample photos on the 64 MP main camera

In good light, the sensor operates at low ISOs and produces good image quality with reasonably high detail and dynamic range. True, even at the lowest ISO 100, artifacts from image processing algorithms are noticeable. First of all, a kind of looseness of some parts of the image catches the eye.

Snapshot on Xiaomi Redmi Note 8 Pro

Snapshot on Xiaomi Redmi Note 8 Pro

Snapshot on Xiaomi Redmi Note 8 Pro

Snapshot on Xiaomi Redmi Note 8 Pro, crop

Snapshot on Xiaomi Redmi Note 8 Pro

Snapshot on Xiaomi Redmi Note 8 Pro

Snapshot on Xiaomi Redmi Note 8 Pro

Snapshot on Xiaomi Redmi Note 8 Pro

On close inspection of the photos, it feels like the optics can't cope with all 64 megapixels. The edges and corners of an image in 1: 1 viewing can lose a lot of detail.

Image quality deteriorates greatly from using the built-in image filters. When using filters such as "bright" or "dim" and others like that, detail suffers greatly, and the final image when viewed 1: 1 looks like a mess of pixels. The picture looks best with default settings.

By default, the phone imprints a watermark that identifies the phone model from which the photo was taken. A kind of built-in advertising for those who are too lazy to disable this function in the settings.

As soon as ISO crosses the threshold of 140 units, stronger noise reduction algorithms come into force, which completely eat up the image details, after which there is no sense from 64 MP. The algorithms preserve the contours of objects, but the image details are completely lost. In such a case, it is best to use AI Intelligent Mode, which will automatically enable 16MP mode and enhance the final images.

Tetra HDR is very useful and dramatically improves the dynamic range of your images. I would even advise you to almost always shoot in this mode. To make it always work, you need to turn off AI mode and turn on HDR. With both HDR and AI enabled, HDR only works when selected by AI. For the camera to shoot in this mode by default, you need to select “remember settings” in the menu.

Color rendering does not suffer from anything particularly bad, but white balance the camera installs quite correctly. The bokeh is hard enough.

Sample Photos

The camera was used with a stock processor (program) responsible for photo and video filming.

View and download original photos from the main sensor Redmire Xiaomi Note Pro 8 you can go to Google Drive at this link (many JPEG files). In the future, I plan to add more and more examples of photos to the gallery on Google Drive.

UPDATE

A few more photos.

UPDATE 2

Video with examples can take a look here и here.

 

My experience

At first, I was strongly and pleasantly surprised by the capabilities of the main camera. Xiaomi Redmi Note 8 Pro 6 / 128GB, especially on the pictures sent to me in Viber (pinched and reduced). But when I took the sample photos on the flash drive from my mother and studied them in detail, my fuse faded a little. However, it is often seen that the picture was taken with a phone. Although in many cases the main sensor Xiaomi Redmi Note 8 Pro 6 / 128GB can produce pictures with stunning phone-like detail.

In social networks here и here I asked subscribers what the attached photos were received for. Opinions were very different - who guessed right away that it was a phone, someone put forward completely different assumptions that it was shot with SLR cameras, someone indicated the brand of the lens. A poll like this shows how much cameraphones have evolved lately.

Subjectively: if we abstract and try to compare, then the main module Xiaomi Redmi Note 8 Pro 6 / 128GB in general, it barely reaches the level of old cropped cameras with APS-C sensor of 2007-2010 and kit lenses of class 18-55 / 3.5-5.6. To some, this may seem like a weak result, but in fact it gives huge opportunities.

Materials on the topic

  1. Smartphone Impact
  2. Subpixels
  3. What's next?
  4. Battle of Megapixels
  5. Gigapixels
  6. The future of amateur photography in one picture

Comments here on the site do not require any registration. In the comments, you can ask a question on the topic, or leave your feedback, or describe your experience. For the selection of photographic equipment, I recommend E-Catalog. Many little things for the photo can be found on AliExpress.

The material was prepared by Arkady Shapoval. My Youtube channeland Radozhiva's group on Facebook и VK.

Add a comment:

 

 

Comments: 87, on the topic: Xiaomi Redmi Note 8 Pro, 64 MP Samsung ISOCELL Plus sensor

  • iskreniy

    I take photos on R N8P. Excellent for his money, but Arkady correctly noticed that he was not up to the old DSLRs. In general, this is physically impossible due to the matrix and the lens. Although there is a whole class of photographers, with phones that do work for money, because with such a device + - you can do well.

  • Pokemon

    An interesting article on the topic of cameras in mobile phones and mobileography in general and what can be expected in the near future (and what already now):
    http://vesnins.ru/vychislitelnaya-fotografiya-budushhee-fotografii-eto-kod

  • Sergey K

    Thanks, interesting information! What do you say when I send you a photo from the old Canon A620, where there is only 7.0 megapixels? And he was one of the best back then on dpreview.com, and this is my favorite site for choosing a photo technique.
    Honestly, this cameraman of mine still takes incredible photos. How will a modern camera phone fight it? Who will win? Let's compare for fun!

    • BB

      Now my Samsung M31 has the same sensor as in the article. Comparing photographs from it, and from the Olympus 'ultrazoom' around 2004-2005. with a 4MP matrix, in terms of detail, the ancient Olympus will probably be better. Optics resvet, as they say.

      • Victor

        Are you joking? In terms of detail, I compared 8 (and 12) MP Canon and isocell even “48” (actually 12) MP, a smartphone sensor on the head in front, with a Google camera.

        It is larger, it is fresher, it has a fixed lens (to the question of "optics decides"), and much more software and hardware resources.

        There is not even anything to talk about, actually.

        • Victor

          It is inferior only to old DSLRs, for obvious reasons, but it is inappropriate to compare with soap dishes with a sensor size of 1 / 2.5 - 1 / 2.7.

        • Arkady Shapoval

          Yes. even if all 4 MP were ideal, then 64 MP from this Redmi is noticeably better in detail

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English-version of this article https://radojuva.com/en/2020/08/xiaomi-redmi-note-8-pro-64-mp-osnovnojj-kamery-samsung-isocell-plus/