Painting with light: How Smart-ISO Pro captures lifelike HDR images
on Feb 10, 2021
Taking a picture of the stunning landscapes and vistas we encounter in daily life using our smartphones can bring about challenges. Sometimes, the images can differ from what we see with our own eyes: shadowed areas come out too dark, the sky becomes overexposed, and subtle details essential to the view can become obscured.
Dynamic range, which refers to the brightest and darkest parts of a scene, is key to creating vibrant images with your smartphone. However, even the best digital cameras available today are unable to match the dynamic range of the human eye.
To maximize the dynamic range on smartphone cameras, Samsung engineers developed an innovative High Dynamic Range (HDR) solution for mobile image sensors – the Smart-ISO Pro.
How Image Sensors Capture Light
To understand how Smart-ISO Pro creates dynamic and vivid images, it is key to first understand how image sensors capture light and how sensor’s light sensitivy works.
In digital photography, the conversion gain determines the light sensitivity of the image sensor and is utilized to convert light into voltage. When shooting in low-light environments, details in dark areas can be lost if the conversion gain is too low. By contrast, the image sensor may not be able to retain sufficient color information if the conversion gain is too high in brighter environments.
Most mobile image sensors have a fixed conversion gain. This makes it challenging for smartphones to consistently capture high-quality photos across different lighting environments. The problem can then become even more pronounced in mixed lighting environments with extreme lighting discrepancies, such as backlit portraits.
Pro-grade Photography, Made Simple
To ensure smartphone cameras can deliver clear images even in diverse lighting situations, Samsung developed Smart-ISO technology for its image sensors. This solution equips image sensors with two levels of conversion gain, high and low ISO mode, allowing the camera to select the optimal settings depending on the environment.
When the lighting is low, high ISO mode converts light to voltage with higher conversion gain to express adequate detailing in shadow while reducing noise in the image. Low ISO mode also maximizes the capacity of each individual pixel to prevent oversaturation and to enhance color reproduction in brighter parts of the shot.
Following the development of Smart-ISO, engineers at Samsung began exploring ways to combine two levels of conversion gain into a single image sensor in order to improve the dynamic range. The result is Smart-ISO Pro, a HDR solution that enables the image sensor to capture a single HDR photo with the benefits of both high and low ISO modes.
When the smartphone camera takes a photo, Smart-ISO Pro first converts the light information of the scene into the voltage signal in both high and low ISO modes respectively. Next, the technology intelligently combines the outcome of the two modes together to create a final image with high dynamic range. This enables the image sensor to bring out the detailing of darker areas, retain the natural color of highlight areas, and ultimately produce images that are true-to-life.
Bursting With Color
The power of Smart-ISO Pro technology goes beyond its ability to precisely capture contrasting light and shadowed areas. With 12-bit color depth support, the technology also delivers unparalleled accuracy in color reproduction. Pixels in image sensors record color information through binary digits, also known as bits. The more bits per pixel, the more colors the sensor can produce.
By combining the information from two 10-bit images together, Smart-ISO Pro can express over 687 billion colors, which is 10 times more than a single 10-bit image. When shooting a smartphone’s pro mode, 12-bit HDR images can be saved in RAW format, giving users greater flexibility when it comes to adjusting exposure, white balance, color and more with no concessions.
The integration of Smart-ISO Pro into Samsung’s ISOCELL image sensors is just another way the company is constantly endeavoring to provide users with pro-grade mobile photography solutions. Take a look at the video below to see the uncompromising Smart-ISO Pro technology in action.