We’re not out of tax season yet, but it’s already clear that the two biggest trends in smartphone imaging in 2023 are bigger sensors and bigger resolutions. Manufacturers like Vivo and Xiaomi are putting larger 1-inch-type sensors in their phones, leaning into the light-gathering and compositional advantages of a larger imager. In the other corner, Samsung is squeezing as many pixels as possible onto a smaller sensor, betting on pixel binning and multi-frame processing to make up for the performance shortfall.
So which way is correct? If we were dealing with traditional cameras, this would be more obvious: all things being equal, a bigger sensor wins every time. but all things are No Par par when it comes to smartphone cameras. They capture multiple frames to boost dynamic range, combine pixels in response to lighting conditions, and automatically combine exposure in near darkness. Gone are the days of opening and closing shutters.
I shot for a week with the 200-megapixel Samsung Galaxy S23 Ultra and the 1-inch Vivo X90 Pro, and the results were surprising. Sure, a bigger sensor wins out on some things. Compared to the S23 Ultra, its RAW files are less noisy in low light. There’s also a shallow depth of field to play with outside of portrait mode. But when I let both cameras make their own decisions about exposure settings and processing—and posed with extremely challenging subjects like a running baby—the advantages of a larger sensor diminished dramatically.
Censors Are Just Part of the Story
When I compared the images there was something obvious that I missed: Sensors are just part of the story. There is the lens, the hardware that processes the image data, and the software that analyzes the scene in front of the camera. The theoretical performance of a sensor is one thing; How all those parts work together with real-world themes is another matter.
First, some housekeeping. Both the Vivo X90 Pro and the Samsung Galaxy S23 Ultra have multiple rear cameras, but for the purposes of this article, we’re focusing on the main camera on each phone. It’s a 200-megapixel 1/1.3-inch-type sensor with an f/1.7 lens on the S23 Ultra and a 50.3-megapixel 1/1.3-inch-type sensor with an f/1.8 lens on the Vivo X90 Pro. Both have optical image stabilization, but only the Vivo’s has Zeiss branding on its lenses.
Say it with me: The 1-inch type sensor doesn’t measure literally an inch. The way we talk about image sensor formats has something to do with old TV camera tubes. It’s weird. That said, this 1-inch sensor is still huge by smartphone camera standards. This provides roughly 1.8 times more surface area for collecting light than the 1/1.3-inch type sensor on the S23 Ultra.
the more photons the better
To start, let’s take a look at some of the places where the larger sensor has a clear advantage. If two cameras set up with the same exposure capture the same subject with the same framing, you would expect a clearer image from the larger sensor. There is simply more surface area to absorb photons. on Richard Butler dpreview Explains it better, but basically, it’s just physics. The more photons, the better.
To help with capture, the tiny sensor uses a technique called pixel binning to group data from individual pixels so that they act as one large pixel in low-light conditions. In bright light, they act as individual pixels – because there’s enough light to go around, the smaller pixels work fine. It’s like have-your-cake-and-eat-it scenario: You get better low-light performance and the flexibility of a higher-resolution sensor. It’s a sensor technology that’s been in use for years, and even Apple got on board with the iPhone 14 Pro, so you know it’s a trend that’s sticking around.
The pixels on the X90 Pro’s Sony IMX989 sensor are physically larger, and larger pixels collect more light. But when you take pixel binning into account, the X90 Pro still has an advantage over the Samsung. In low light, the S23 Ultra’s sensor is binning 16 smaller 0.6μm pixels to make a much larger 2.4μm pixel. The Vivo X90 Pro makes four 1.6μm pixels by 3.2μm pixels. Both result in a 12-megapixel image (well, 12.5-megapixel in Vivo’s case – Samsung’s down to 12 megapixels).
So yes, the Vivo X90 Pro produces clearer RAW image files in low light than the Samsung S23 Ultra. Here’s what it looks like at ISO 1600 — the S23 Ultra’s image clearly has more noise.
But! They’re single-frame RAW files, and we haven’t brought computational photography into the mix yet. Putting both the cameras in night mode reduces the difference to a great extent. If you look closely, the S23 Ultra’s image still has some color noise in areas of fine detail that aren’t visible in the X90 Pro. But reduced to the resolution you see on a computer or phone screen, they look about the same.
Night mode is well and good if your subject isn’t moving, but the real test for a smartphone camera is with a moving subject in poor lighting conditions – like a white whale for mobile imaging. That’s where the larger sensor format can make a real difference.
Faster shutter speeds freeze moving subjects so you get a faster shot, but it requires a higher ISO so that your overall image is bright enough. Since the larger sensor produces less noise in high ISO images, it is expected to be able to use faster shutter speeds in low light and come up with decent images of moving subjects. Computational photography makes it a bit more complicated than that because shutter speed and ISO are kind of fluid concepts when you’re compositing multiple frames, but the basic principle of “the more light, the better the photo” roughly applies here.
Sadly, we haven’t found our white whale yet. Both the Vivo X90 Pro and the S23 Ultra preferred to stick to a shutter speed of 1/120 second when I was taking pictures of my baby in the standard camera mode. It’s fine if he’s not moving much, but it’s not fast enough when he’s running from room to room (his default speed).
The better baseline noise performance of the larger sensor doesn’t help much here either. The X90 Pro’s images don’t look any more detailed than the S23 Ultra’s — and oftentimes, the S23’s images look better, even at higher reported ISOs.
In the scene below, both cameras reported an ISO of approximately 320 and a shutter speed of 1/120 second. The S23 Ultra images flat-out look better.
More pixels – or, at least, a more aggressive application of computational photography – looks like it goes a little further from here.
But wait, there are lenses!
Other The other thing about the bigger sensor is that it has a bigger lens attached to it. It is a necessity of sorts. It’s also part of the whole better-in-low-light equation because larger lenses generally have larger apertures. Same is the case with the X90 Pro. On paper, the S23 Ultra has a wider aperture at f/1.7. As far as phone cameras go, a larger aperture is generally better – it lets in more light and gives a bit more depth of field control. But the f/1.8 aperture on the X90 Pro is really important Big Compared to the S23 Ultra because the overall lens is bigger.
If you factor in the sensor format and make an apples-to-apples comparison, the S23 Ultra’s f/1.7 aperture actually behaves like an f/6.5 full-frame lens—at least as far as light-gathering and field of view go. There is a relation of depth. The X90 Pro’s f/1.8 lens is equivalent to f/4.9 on full-frame, letting in more total light and providing a shallower depth of field. If you want to debate about the concept of equivalence, please report to dpreview forum and tell them I sent you.
The bigger aperture is good news for the X90 Pro, but the bad news is that it’s not great, despite the little blue Zeiss badge on the lens. It’s sharp in the center, but there’s a clear drop in quality just outside the center portion that looks like spherical aberration to me. There are highlights and general blurriness around out-of-focus areas of the frame, which looks as if someone has applied a little Vaseline to the lens.
Spherical aberration is somewhat unavoidable when you’re projecting an image through curved glass onto a flat plane, but I haven’t seen it this way in any smartphone camera I’ve tested over the past year and a half. Maybe this is one of the perils of early adopters of this relatively new sensor format.
In any case, you get more natural bokeh with the X90 Pro’s camera. It also comes with a side of mildly obnoxious lens aberration. Putting a big-name brand on your camera doesn’t magically make it better, but Vivo is hardly the first to try it anyway.
who wore it better?
I am glad that the 1-inch sensor format is making its way to more smartphones. It’s great to be able to get a little more background out of focus without flipping to portrait mode. And the RAW data speaks truth: a bigger sensor is still better for low light noise performance. The photography snob in me would prefer a camera with a larger sensor that produces cleaner images rather than the noise of a higher-resolution sensor in rendering with more pixels and processing.
At the end of each imaging pipeline, there’s only one thing that matters: the image.
But at the end of every imaging pipeline, only one thing matters: the image. The X90 Pro is technically superior in some ways, but as an overall package, I’d pick the S23 Ultra every time. Samsung’s color tuning and HDR aren’t always my favorites, but in most real-world situations, it just outperforms the X90 Pro. Either the extra pixel or the saver computational technology gives Samsung an advantage, and I’d gladly take it over the better high ISO RAW files any day.
Both Samsung and Vivo are well aware that a camera is much more than its sensor, and it looks like the S23 Ultra has all the parts that make an imaging system sync up better than the Vivo’s. The X90 Pro may not deliver on every promise of the larger sensor format, but I highly doubt it will be the last 1-inch sensor smartphone I’ve tested this year – far from it.
Photography by Allison Johnson / The Verge