On April 6, Samsung Electronics Japan announced the new flagship models “Galaxy S23” and “Galaxy S23 Ultra” for Japan. Along with the announcement, Dr. Joshua Cho, vice president of Samsung headquarters, visited Japan and conducted a group interview.
Cho is the vice president of Samsung Electronics’ visual solutions team in South Korea and the chief of camera technology development for Galaxy smartphones.
Galaxy VS single-lens camera, four advantages
Mr. Cho introduced the advantages of the Galaxy S23 Ultra compared to digital single-lens cameras in the following four points.
- (1) Galaxy S23 Ultra is compact and easy to use (compared to dedicated cameras)
- (2) Bright and clear image capture by pixel binning technology
- (3) OIS (optical image stabilization) and VDIS (electronic image stabilization for movies)
- (4) Enhanced with advanced AI technology and multi-frame correction
In particular, the S23 Ultra has enhanced (2) pixel binning and (3) image stabilization.
Galaxy S23 Ultra is equipped with a 200 million pixel camera and “pixel binning” has evolved
Increasing the number of pixels in image sensors is one of the trends in smartphone cameras. Of the Galaxy S23 Ultra’s four-lens cameras, the wide-angle lens is equipped with a high-resolution sensor of 200 million pixels. Pixel binning is a technology in image sensors that “bundles and uses” these high-pixels.
The main camera on the back is 200 million pixels. It also has a camera for optical step zoom equivalent to 3x and 10x
A high-megapixel sensor can record high-definition photos in well-lit areas, but it doesn’t perform well in low-light areas. Since the amount of light that can be taken in by one pixel is limited, it has the disadvantage of being prone to blackouts. For example, a fine image can be expected in a sunny day outdoors or in a photography studio, but it is often the case that a sufficient level of detail cannot be obtained with the illuminance of indoors during the day. Using pixel binning can compensate for this weakness.
In the case of the Galaxy S23 Ultra, 16 adjacent pixels of the 200 million pixel sensor can be bundled and treated as a sensor equivalent to 12.5 million pixels with a large size per pixel. This allows you to take bright pictures even in a dark room by capturing a lot of light. There is also an intermediate mode between 200 million pixels and 12.5 million pixels, and it is also possible to bundle four pixels and operate as a “sensor equivalent to 50 million pixels”.
In other words, the Galaxy S23 Ultra’s 200-megapixel camera records high-definition 200-million-pixel outdoors in bright light, achieves both brightness and resolution equivalent to 50-megapixel indoors, and operates at 12.5-megapixel in low-light environments, making it dark. You can control it in three stages to brighten the details of the part, and obtain the optimal photograph under various exposure environments. The recording process itself at high pixels has also been improved, and even when recording at 200 million pixels, it is said to be shortened to regarding 0.7 to 0.8 seconds per second.
You can also manually set recording at 200 million pixels by selecting “200MP” in the resolution setting.
Improved image stabilization
It has been greatly improved with the Galaxy S23 Ultra, but it is camera shake correction. There are two types of camera shake, an optical type that uses a physical mechanism and an electronic type that performs correction processing on data, but the S23 Ultra is enhanced on both sides.
In the optical image stabilization (OIS), the correction angle has been expanded from the conventional 1.5 degrees to 3 degrees. The electronic image stabilization works better when shooting video.
With these two image stabilization functions, even if you shoot handheld while walking, you can shoot smooth images as if you were shooting with a gimbal.
The biggest difference from single-lens cameras is “multi-frame processing”
Mr. Cho emphasized that multi-frame processing is the “biggest difference from digital single-lens cameras.”
Multi-frame processing is the process of taking several to several hundred shots and combining them into a single image when the shooting button is pressed once. A prime example of this is HDR photography. In a room where there is a difference in brightness due to backlight, the smartphone camera takes multiple frames and synthesizes them in order to depict dark areas without causing blown-out highlights. This process is also used for noise reduction and digital zoom.
The Galaxy S23 Ultra also applies multi-frame processing to videos. The 12-bit Super HDR video recording function allows you to shoot vivid videos with less backlight.
Multi-frame shooting is also used in digital single-lens cameras, but in the case of smartphones, larger-scale processing can be realized. This is because smartphones have high-performance processors, and depending on the model, an NPU (AI processing chip) can be used.
Multi-frame processing, which improves image quality with a small lens and image sensor, is incorporated into the camera shooting function by many smartphone manufacturers. So, when I asked Mr. Cho, “What are Samsung’s unique strengths in Galaxy?”, he replied as follows.
The quality of the data used in machine learning is important to achieve high accuracy with AI algorithms. The higher the quality of the training source image or video data, the higher the accuracy of the final output. Samsung owns a large amount of training data in-house, and is also working to generate high-quality training source data in addition to data taken in the real world. We are also researching model weight reduction (quantization) so that we can provide optimal algorithms. The accumulation of such research and development is behind the provision of high-quality services using AI on smartphones.
“Astronomical hyperlapse” to shoot the starry sky with just a smartphone and a tripod
Along with the launch of the Galaxy S23 series, a new shooting function is provided. In the standard camera app, the “celestial hyperlapse” function has been added. It captures the movement of the stars in the night sky every few minutes and displays their trajectories. No special equipment is required, and you can shoot just by setting your smartphone on a tripod. This feature has been requested by many users.
Shooting app “Expert RAW” enables 50-megapixel recording
In 2022, Samsung started offering a shooting app “Expert RAW” dedicated to Galaxy. It is an app that provides a shooting experience like a professional camera product on a smartphone, and records photos in RAW format (.dng files) that can be edited flexibly following shooting. It also has a function to link with Lightroom Mobile, so you can seamlessly transfer to images following shooting.
This Expert RAW also has an “astrophotography” mode as a new feature. By selecting the optimal shutter speed for the astronomical object, you can record the starry sky in high definition. In addition, “multiple exposure shooting” has also been added. A photo that combines two or more photos.For example, you can create a photo with a unique atmosphere by combining a selfie and a pattern.
Expert RAW also supports “RAW shooting with the in-camera” by updating. In addition, it supports “RAW shooting with 50 million pixels” as a function only for Galaxy S23 Ultra.
Mr. Cho explains the reason why it does not support RAW recording at 200 million pixels as follows.
Expert RAW is focused on providing RAW that can be edited flexibly, so it does not provide a function to record at 200 million pixels. Expert RAW generates RAW through multi-frame processing, but it is difficult to apply multi-frame processing to 200 million pixel data as it is with the current machine specifications. We believe that when the semiconductor design process becomes more detailed and more advanced calculations become possible, we will be able to provide it at that time.
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