The Apple iPhone X keeps a similar dual-12MP (wide+telephoto) camera setup as the iPhone 7 and 8 Plus. While the wide-angle sensor sits behind the same f/1.8 lens, the telephoto one has been updated with optical stabilization and new wider f/2.4 lens. A large piece of scratch-resistant sapphire glass is supposed to keep them away from harm's way.
The iPhone X, just like the 8 Plus, has Sony Exmor RS sensors - the wide-angle camera has a 1.22 µm pixel size, and the telephoto camera has a 1.0 µm pitch as before.
The iPhone X keeps the new image processor and noise reduction algorithm, and with the help of the A11 chip, the iPhone X is capable of real-time image and motion analysis - body and face detection. The video capturing also benefits from the new powers - there are 4K at 60fps and 1080p at 240fps modes.
Apple is now aggressively pushing AR and AR-related apps, so all camera lenses are factory-calibrated to provide superior performance in AR.
Apple also advertises the new iPhones to have "deeper pixels" which is another name for the camera sensor using deep trench isolation tech. Deep trench isolation is not a new technology and was first introduced on the iPhone 6s generation - also available on quite a few Sony Xperia (DTI) and Samsung Galaxy (ISOCELL) smartphone cameras. It's a technology for better pixel isolation on the sensor itself, which prevents light leakage between the neighboring pixels and thus improves the overall photo quality. There is no denying its benefits.
The quad-LED dual-tone flash from the iPhone 8 Plus is also available on the X, and it supports slow-sync flash. It keeps the shutter open for a bit longer, letting in some of the ambient light, making the image look more natural and not as contrasty as with regular flash images.
The Portrait mode with Portrait Lighting is here to stay, now available on both the main and selfie cameras. The camera scans the scene, identifies the face of your subject and (in real time, mind you) adjusts the tone curve of the face to make it better lit. And you can adjust the effect after you've taken the shot.
The camera also comes with a new file format, yes, JPG's days are numbered. At least as far Apple is concerned. iOS 11 now saves all images in the HEIF file format and videos in HEVC (H.265) video format by default. This is done because of the more efficient compression these files provide. We can confirm - photos take about half as much space as before (1.4MB HEIF vs. 3MB JPG), and the same goes for videos.
The phone will convert the images to an older format if shared from within iOS, but if you copy images over USB, the original files are transferred only if you have macOS High Sierra. If not - you will get converted files - both pictures and video - in JPG and H.264 formats. The conversion is done in real-time while you are transferring the files without you even noticing.
Don't you worry, you can choose the format you prefer, so if you don't like having your media stored in the new format - you can choose Most Compatible from Settings instead of High Efficiency. This way no conversion will be done while transferring, but you will waste away storage.
The improved compression by these file formats doesn't come at the expense of quality. After careful pixel peeping, we saw no difference in quality between HEIF and JPEG, and if there was a marginal difference between H.264 and H.265, it was in H.265's favor. On the other hand, quality with videos varies depending on how busy the scene is so the jury is still out on whether they are universally better than the H.264 ones. Furthermore, only the high-efficiency mode allows you to use the new 4K at 60fps and 1080p at 240fps video recording modes.
The daylight photos taken with the iPhone X are great. There is lots of resolved detail, low-noise, and impressive dynamic range - all that with HDR turned off. No corner softness on the iPhone X images, true to life colors and white balance, superb contrast, and always accurate autofocus.
If you leave the auto HDR option on, sometimes you may notice some of the shots were taken with HDR turned on and the only difference is the even lower noise levels. Apparently, Apple also uses the multiple frames stacking to decrease the noise levels further.
Of course, when HDR is needed (and that would be rare with this dynamic range), it won't fail you for sure.
The one thing that stays the same as before is the somewhat watercolor-like foliage presentation at 1:1 magnification. The iPhones have been this way for years, and Apple may want to put some work here, too.
We snapped a few samples with the iPhone 8 Plus at the same scenes, and found out all the shots to be identical with the once snapped with the iPhone X.
The telephoto camera produces the same high-quality images as the wide-angle one and comes in handy when you need a bit of zoom. It has optical image stabilization and wider lens on the iPhone X, which means it shoots at higher speed and thus reduces the risk of motion blur.
While the telephoto camera is better on the iPhone X, it shows no differences in daylight when compared to the iPhone 8 Plus telephoto samples.
Now, let's see what happens in low-light. The OIS allows the iPhone X to drop the shutter speed to as low as 1/4s when shooting handheld. This combined with the wide aperture, the new sensor, and the new image processor allows it to take great low-light images.
There is plenty of detail in all-low light shots, the colors are mostly accurate, and the dynamic range is still impressive all things considered.
The telephoto camera now has OIS, too, and a relatively wider f/2.4 aperture than before, so you'd think Apple will finally enable this one to be used in low-light. And you'd be wrong. In those scenes, the phone will still stop using the telephoto camera and would instead switch to cropping the output of the main camera to achieve the zoomed effect. This, of course, takes its toll on image quality. Check those digitally zoomed photos below.
We managed to trick the phone into giving us a night photo from the tele camera. And the results were a surprise - the tele camera produced the much better photo. It's noisy, but it's visibly sharper and preserves detail lost in an upscaled image from the wide-angle cam.
Look at the texture of the wall, the metal bars on the windows, the sharp lines of the stairs, the foliage to the side. The extra noise was to be expected with the higher ISO used by the tele camera (250 vs. 100). But it also used a shorter exposure, 1/8s vs. 1/4s, which is better for moving objects. The white balance of the image is an issue, though, with a strange red tint. But that shouldn't be too hard to fix.
Enabling the telephoto camera in the dark should be an easy software change for Apple. It's not hard to imagine that the team meant to do that but ran out of time before the launch, there's more than one story of iPhone X's troubled production. Unless this was an intentional move, but we have to admit we don't see the benefit of it.
We also decided to test the slow-sync flash. As promised it lets in some of the ambient light and makes the image look more natural. Or to simplify it - you don't look like a zombie anymore. But using it requires holding the camera extra still.
Unfortunately, the flash on the iPhone X turned out somewhat weaker than the one on the iPhone 8 Plus. Whether it's because of the different position, cover glass, or simply reduced power, we don't know, but the pictures speak for themselves.
You can check out how the iPhone X 12MP wide-angle and telephoto cameras perform in our dedicated compare tool. The iPhone X surprisingly used its telephoto camera in our low-light studio test, and you can see it does better than the digitally zoomed samples of the iPhone 8 Plus and Galaxy Note8.