Samsung Galaxy S21 Ultra’s killer photography tech revealed — here’s how it works

Samsung Galaxy S21 Ultra
(Image credit: Future)

Samsung's just shown off the secret sauce that makes its Galaxy S21 Ultra so good at photography.

We already know that the S21 Ultra's 108MP camera is one of the highest resolution cameras you can get on a phone right now. But a new video explains the underlying HDR technology that helps this enormous sensor capture pictures with amazing color and lighting.

The sensor's "Smart-ISO Pro" technology is explained in a YouTube video posted by Samsung. This is a complex bit of tech but it boils down to taking two images and combining the best parts into one final picture. 

The two raw images are taken at two levels of light sensitivity, high and low. The sensitivity of a sensor to light is expressed as an ISO number, hence the name Smart-ISO. Samsung's original version just allowed the camera to pick which level was the best for a given image, but the new Pro version enables the two levels to be combined as explained before.

Combining images like this, a technique called HDR (high dynamic range) imaging, is already a well-established part of smartphone photography. Offering this technology in a camera sensor isn't new either, but Samsung's method of implementing it on a smartphone camera is novel, and the reason why it's promoting it.

The benefit is that you get much more colorful and high-contrast images of subjects with big differences in the brightness of the brightest and darkest areas; say a sunny landscape with dramatic shadows. It's typically been an area where smartphone cameras are weak, since the sensors are too small to capture large amounts of light naturally.

While this sensor is in use on the Galaxy S21 Ultra, Samsung sells this camera to other companies too. It means that we may see other phones like the Xiaomi Mi 11 later this year, which is rumored to use a Samsung-made 108MP camera, also make use of this ingenious photography method. Hopefully we'll find a version of Smart ISO Pro make its way onto other Samsung-made cameras too, so more basic models of future phones like the Galaxy Note 21 or next year's Galaxy S22 will be capable of the same trick.

Unfortunately for Samsung, as good as the main camera is on the S21 Ultra, it only managed second place on our best camera phones list. It gets beaten by the iPhone 12 Pro Max, which goes to show how it takes more than just a clever sensor to be the best on the market.

Richard Priday
Assistant Phones Editor

Richard is based in London, covering news, reviews and how-tos for phones, tablets, gaming, and whatever else people need advice on. Following on from his MA in Magazine Journalism at the University of Sheffield, he's also written for WIRED U.K., The Register and Creative Bloq. When not at work, he's likely thinking about how to brew the perfect cup of specialty coffee.