Samsung’s newly announced Galaxy S20 Ultra offers a new feature that the company is calling “Space Zoom,” which allows its cameras to offer a total combined optical and digital zoom of 100x. That sounds like one of the biggest zooms we’ve seen on a mainstream smartphone, but there’s a lot of nuance to how Samsung’s phone achieves the figure. In short, it’s all down to a combination of optical zooming hardware, image processing, and an exceptionally high-resolution sensor.
At lower levels of zoom, Samsung is relying on a “folded” 4x telephoto lens behind the hole in the back of the phone, which it’s combining with a 48-megapixel sensor. Then, between 4x and 10x zoom, the phone offers what Samsung is calling a “lossless hybrid optic” zoom, which relies on a combination of sensor cropping and binning where multiple pixels are combined into one big pixel. The use of the word “lossless” implies that Samsung doesn’t think you’ll see any loss of quality up to 10x zoom. Then, between 10x and 100x zoom, the phone is using similar methods, but it’s a digital zoom that will inevitably mean less detail as the zoom increases.
This 100x zoom is exclusive to the S20 Ultra. The S20 and S20 Plus, meanwhile, offer a hybrid optical zoom that tops out at 3x rather than 10x, while their maximum zoom levels sit at 30x rather than 100x.
Huawei and Oppo’s phones have previously gone up to 50x and 60x zoom
Samsung’s method of getting to 100x isn’t entirely unique. For example, last year, Huawei used a similar “folded” zoom lens on the P30 Pro. In Huawei’s case, it had an 8-megapixel sensor underpinning the telephoto camera with an optical zoom of 5x and was then able to add data from the camera’s main 40-megapixel sensor to offer a hybrid “lossless” zoom up to 10x. In our experience, we didn’t think this lossless claim was 100 percent accurate due to a slight loss of detail at 10x zoom, but it was a small drop in quality overall. The total digital zoom topped out at 50x, but well-lit images stopped being usable beyond around 32x. Meanwhile, the Oppo Reno 10x Zoom offered software-enhanced zooming up to 60x and used a similar hybrid system to zoom up to 10x. In our testing, the Oppo produced sharp, well-exposed 13-megapixel zoom shots in good light that quickly turned blurry at night.
The S20 Ultra’s main sensor has a resolution of 108 megapixels
One of the bigger hardware differences between Samsung, Huawei, and Oppo’s phones is that Samsung is using much higher-resolution sensors for both the S20 Ultra’s periscope and main cameras. While the P30 Pro’s telephoto camera had a resolution of 8 megapixels, and the Reno 10x Zoom’s was 13 megapixels, Samsung is using a 48-megapixel sensor with its periscope lens. Then, the S20 Ultra’s main camera has an incredibly high-resolution 108-megapixel sensor, compared to the 40-megapixel sensor on the Huawei and 48-megapixel on the Oppo. The two sensors combined give Samsung’s handset access to more data, which could potentially result in more detailed images.
Increasing the resolution of a sensor can cause its own problems, such as worse low-light performance due to having smaller individual pixels. Samsung claims to have found a solution to these problems, but we won’t know whether it’s done so for sure until we can fully test the feature for ourselves.
Having said all of that, the relationship between smartphone camera specs and real-life performance is very hard to predict. Apple’s latest round of iPhones, for example, produces impressive photos from a selection of 12-megapixel camera sensors. As my colleague Sam Byford has made clear in the past, “megapixel count or even physical sensor size just aren’t that meaningful at this point — the image processing pipeline and computational photography make a much bigger difference to how well your phone’s camera will perform.”
We’ll be putting Samsung’s 108 megapixels and 100x zoom to the test in our upcoming review, so stay tuned.