Both the iPhone 7 Plus and the Pixel XL have 12MP cameras, so they must be the same, right? Well, of course not.
For starters, the iPhone 7 Plus has two of those. A couple of 12MP sensors on the back, the primary-er 1/3" mated to a 28mm-equiv. f/1.8 lens with OIS, the other one - a smaller 1/3.6" imager behind a longer but dimmer 56mm-equiv. f/2.8 lens (no OIS).
What that does for you is offer 2x zoom, sort of, sometimes. 'Sort of', because you can have 28mm wide-angle shots, or 56mm 'normal' ones, while everything in between is digital zoom from the wide-angle camera.
And then 'sometimes', because when there's not enough light, and you still want the 2x zoom, the iPhone 7 Plus will use the wide-angle camera, digitally zoomed to the 56mm field of view (without warning you as is the Apple way). The Cupertino company apparently doesn't trust the combination of a smaller sensor with dimmer non-OIS optics.
The dual cameras are also what's enabled Apple to implement a Portrait mode, which applies a bokeh effect to the background, while keeping the subject in focus (most of it).
The Pixel XL does other tricks, though. It all starts with a large 1/2.3" sensor with 1.55 micron pixels (Xtra Large, if you will - don't know what we'd do with this pun if this was the regular Pixel that has the same sensor). The lens is a 26mm-equiv. with an f/2.0 aperture - so, wider than the iPhone's wide, only dimmer by a third of a stop.
Google's magic lies in the Pixel's HDR+ capability. While conventional HDR practices rely on exposure bracketing that starts when you hit the shutter release, on the Pixel the camera is already capturing shots as soon as you open the app. It's keeping 9 of these at any given time, all of them with the same exposure geared towards keeping highlight details.
Once you hit the shutter release, the 9 images are stacked for eliminating noise and the Pixel XL is actually dramatically reducing it. The shadows may be underexposed, but they have true colors and they can be brightened up with tone mapping. Taking the photo is instant too - there's no delay once you tap on the shutter, as the 9 images have already been captured.
That's what Google says is happening under the hood, but for all the magic (magic, math, same thing) the end result is superb. Sharp, detailed photos with great contrast and dynamic range, we're quite impressed by the Pixel's output, to put it mildly. Colors are punchy, there's no denying that real life isn't as vivid, and yet we've seen even more saturation in LG's recent cameraphones.
On the other hand, the iPhone is much more reserved in terms of color rendition straight of the camera. Per-pixel detail isn't quite as high either - look at high-frequency details like foliage and you're bound to see the difference.
The Pixel XL itself has a complicated relationship with colors. The HDR+ auto mode doesn't just change exposure, it also dials up saturation a bit, and makes things slightly warmer, too. We don't see the average user complaining about this - in fact we believe it's exactly what they'd want.
The iPhone 7 Plus has another key feature that deserves a mention - Portrait mode. In theory, it takes data from both the wide and tele cameras and analyzes it to determine the subject. Once it does, it strives to leave only that in focus while blurring the background in an attempt to recreate a portrait lens' ability to render smooth bokeh.
It works, and it doesn't. You stand a higher chance of success if you're facing the camera, as opposed to being at an angle. Beards against foliage doesn't work, and may end up losing parts of your face to bokeh. Stray hairs also tend to get lost.
That said, it does produce very pleasing results when it gets things right. Only don't sell your DSLR and fast portrait lenses just yet.
Oh, by the way, the iPhone 7 Plus is great in that it keeps the original photo, as captured by the sensor, alongside the one with portrait mode applied - You may often find yourself liking the original better. Same with HDR, now that we mention it.
The two phones take rather different approaches to dealing with high dynamic range scenarios. In the first sample, the iPhone 7 has done a very subtle job of compressing the image and pulled a tiny bit of detail from the highlights, while also just slightly bringing out the shadows - more or less what you'd expect an HDR mode to do, only very little of it.
The Pixel is nowhere nearly as conservative, and recovers a lot more of the sky already in HDR+ Auto, though some portions of the tree trunks end up pitch black. But just because the iPhone chooses not to render the same areas black, doesn't mean there's discernible detail there. With HDR+ On the Pixel's shot is nothing short of eye candy.
The second example, admittedly quite extreme, produces some very odd results on both phones. The iPhone, for one, goes for an overall darker exposure for its HDR shot - okay, salvage those highlights, but do something about the shadows, please.
The Pixel delivers more predictable results in terms of exposure. With HDR+ in auto mode, we see a green color cast appear out of nowhere, and it's not looking good. With HDR+ in the on position, the Phone by Google has recovered a lot of detail in the shadows, while also keeping noise there lower than in auto.
In low light the image stacking gives the Pixel a significant advantage once again, allowing it to preserve a lot of fine detail and texture. That said, even with HDR+ disengaged, its images are sharper than the iPhone 7's, even at the expense of some more noise. The iPhone's insistence to shoot at ISO100 and low shutter speeds doesn't seem to give it an advantage and might cause issues with camera shake and motion blur (provided, of course, that it reports the EXIF data truthfully).
The two smartphones shoot good panoramas, but we like the Pixel's more. There's a significant gap in resolution - the iPhone's panoramas are about 4,000px tall, versus the Pixel XL's 2,500px. But in reality, the Pixel's images have more detail and definition despite that. Look at the grass and trees and you'll see what we are talking about.
Then there's the matter of colors. In the previous flagship comparison we noted the iPhone 7's muted output and a week doesn't change much. Sure, you could edit the image and pump up the saturation, but straight out of the camera app you're getting rather dull colors.
What we're not particular fans of in the Pixel's panorama mode is the need to align the viewfinder to onscreen dots instead of just sweeping. It's not a deal breaker by any stretch, but it's not quite as convenient.
There's a whole lot to love about the Pixel XL's front facing camera, while the iPhone 7 Plus' is just okay. 8MP vs. 7MP doesn't sound like much, and it really isn't. What immediately makes a world of a difference, even before we start pixel peeping, is the coverage - the Pixel just gets a lot more in the frame.
The Pixel's images are sharper with more detail, and truer colors, particularly with HDR+ off. In auto it leans a little too much towards pink, but even so it's definitely closer to reality than the yellowish iPhone representation - knowing the guy front of the camera, trust us, that's not his skin color.
In low light, the iPhone 7 Plus just doesn't stand a chance, particularly when shooting with available light. Truth be told, the Pixel XL itself doesn't stand a chance against its own HDR+ shots either. The stacking has done a job so good it's hard to believe and has preserved fine detail and colors in a very convincing way.
Now, the iPhone 7 Plus does have a screen flash feature, which can help immensely in particularly dark settings. The Pixel sadly has no such option built-in, and this one goes in the iPhone's favor.
For the more technically inclined among you, make sure you check out how the Pixel's HDR+ Auto mode compares to its own HDR+ off and the iPhone 7 Plus in our test posters under controlled lighting.
Still images winner: Pixel XL. Detailed low-noise images with pleasing colors day and night, from both the primary and the selfie cameras.