iPhone 5S review: Apple’s former flagship makes the iOS 12 cut

iPhone 5S review: Performance

For the real changes, you have to go under the surface. Inside, the iPhone 5S is a brand-new phone with a new System on a Chip (SoC), the Apple A7. Now rolled out to the iPad Air and iPad Mini with Retina Display, it was the first 64-bit mobile CPU.

It sounds exciting, but the real benefits are a little harder to understand. First, and not so importantly, 64-bit chips can address more memory than 32-bit chips. This is important in a desktop computer, where a 32-bit chip can only handle around 3.5GB of RAM, but in a smartphone where 1GB or 2GB of RAM is all that’s required, this is only something that will become important in the future.

More importantly, moving to 64-bit means that the Apple can use a newer ARM architecture. The ARMv8 core now has double the number of general-purpose registers, compared to the ARMv7 used in the A6, with 31 64-bit wide registers. This means that the CPU has to access the comparatively slow system memory less, improving speed and efficiency, regardless of whether an application is 32-bit or 64-bit.

Finally, with a new architecture, Apple can use more optimisations to improve the speed of its applications and OS; as developers move to 64-bit, too, we should see these improvements everywhere. That’s by-the-by, but the real proof is in actual performance. Apple’s figures say that the new chip is up to double the speed for graphics and system apps. Our initial tests would seem to show that this is about right. In the SunSpider Java benchmark, the iPhone 5 running iOS 7 completed the test in 708.6ms; the iPhone 5S did it in 416.2ms. The Samsung Galaxy S5 was marginally quicker, completing the test in 391ms, but there’s little practical difference. Given that the A7 is a dual-core chip and the Galaxy S5 uses a quad-core CPU, it shows that it’s not the number of cores that’s the most important thing when it comes to processor speed.

We ran 3D Mark Ice Storm on the phone, too. It completely maxed out both the standard and Extreme tests, not even returning a score. When running Ice Storm Unlimited, we got a score of 14,506. This is amazing performance and puts the iPhone 5S up there with the latest Android handsets.

Raw figures aren’t everything, though. It’s the combination of hardware and software that really makes the difference and, as Apple controls both, the results are fantastic. Despite Android improving a lot, iOS on an iPhone is still the smoothest, neatest user experience with no juddering or slow-downs in any of the operating system’s transitions or animations.

As the A7 is a SoC, it also has some additional silicon for other jobs, including the Secure Enclave for Touch ID and dedicated Image Signal Processor for the camera, which handles some of the effects including image stabilisation, colour correction and light balance (more of this later).

iPhone 5S review: Apple M7 motion coprocessor

This year Apple has added the new M7 motion coprocessor. This low-power part’s job is to collect data from the integrated sensors, including accelerometers, gyroscopes and compasses. It can even do this while the phone is sleeping, making the data it collected available to the CPU when it wakes up. Having this means that the phone can use its sensors more without affecting battery life.

For example, if you put your phone where it has no signal, say in a locker at the gym, the M7 can use the sensors and work out that the phone’s not moving. As it’s not moving, it knows it’s not worth hunting for a signal, so it can save on battery power.

There are other clever uses, too, as the M7 can understand your type of movement, so it knows if you’re driving, walking or running. This is used currently in Apple Maps, which automatically switches driving instructions to walking instructions when you get out of your car. It’s a small addition, but it makes the smartphone, well, smarter.

iPhone 5S review: Battery life

The combination of the new processor, M7 motion process and a slightly larger battery all mean that the iPhone 5S has better battery life than its predecessor. Running at half brightness with Wi-Fi turned off, our iPhone 5S lasted 14h 31m in our video playback test; the iPhone 5 lasted 12h 4m. Apple is also quoting improved 4G surfing time, at 10 hours. We’ve certainly noticed that a charge lasts a lot longer on the iPhone 5S and at the end of the day our phone’s not gasping for power in quite the same way.

iPhone 5S review: Camera

Rather than up the pixel count for the new iSight camera, Apple has got the same 8-megapixel resolution but gone for a sensor that’s 15 percent bigger than the one on the iPhone 5. This means that the pixels are larger at 1.5 microns. In layman’s terms, larger pixels means more light per pixel, which means better low-light performance. Add in the new f/2.2 aperture lens, which lets in more light than the iPhone 5’s f/2.4 lens, and the new model should be able to shoot more detail in low light.

In bright light it makes less of a difference, with both phones producing similarly-as-detailed shots. We’d say the colours and exposure on the iPhone 5S are better, and you get better dynamic range.

The iPhone 5S (bottom) has better colours and better exposure than the iPhone 5 (top)

There’s little to tell between the two in terms of detail. In bright lighting the higher pixel count of the 13-megapixel Galaxy S4 means that there’s slightly more detail in its images, purely because of the higher resolution.

^Looking at the detail, the iPhone 5’s shot (top) is similar to the iPhone 5S’s shot (bottom)

In low light we found that the iPhone 5 generally struggled and noise became a big issue. With the iPhone 5S things are a lot better. In very dark rooms, noise was reduced considerably, while retaining a lot of detail in the image. It’s impressive the difference here.

We also put the iPhone 5S through our photography still life setup, photographing a toy train and cuddly animals under a variety of different lighting conditions. As you can see from the two shots below, in full lighting, the detail is excellent, with plenty of fuzz on the monkey’s cheeks and the toy train retaining its glossy plastic exterior.

Switching the main lights off, so that the scene was dimly lit produced excellent results, too. The colours are a bit more muted, as you can see from the sample shots below, but that’s too be expected given the lighting. However, there’s still plenty of detail in the picture and not much noise, either.

Turning the lights off completely, so that the scene is lit entirely by the spinning fans. This is the hardest shot to deal with, but the iPhone 5S did pretty well. There’s not too much noise in the image and the scene has retained its detail. The blue fan behind the monkey hasn’t come out too well, though, with detail getting blurred.

When you do need to change to the flash, things get even better, as the iPhone 5S has dual-LED True Tone flash. This has one white LED and one amber LED. By analysing the scene, thanks to the image processor on the A7 chip, the iPhone 5S can work out the colour temperature of the scene and fire a flash accordingly. This means it’s goodbye to strange colour casts on image, or unnatural skin tones. In fact, with True Tone pictures no longer look as though they were taken with a flash, it’s that impressive.

You also get better and more natural coverage with True Tone. We shot a few sample shots in a dimly-lit bedroom and the differences are astounding. With the iPhone 5, the front part of the image was too brightly lit, creating a shiny effect that’s the tell-tale sign a flash is being used. It also missed all of the detail towards the rear of the shot, giving everything a slightly unnatural appearance. With the iPhone 5S and True Tone, things are completely different.

You can see that the iPhone 5 (top) loses detail in the distance, but the iPhone 5S (bottom) creates a more natural-looking shot with more detail. We also tried shooting our still-life, which has one tricky setup where there are blue lights. Using the flash, the camera correctly measured and identified the blue hue and corrected the flash to compensate. The results, are rather incredible, with most of the blue light gone from the image, while retaining the detail and colour of the other objects in the scene. We’ve never seen a flash that’s capable of doing that.

There are some new shooting modes, too. First is burst mode, which you see a lot on compact cameras. However, here, it’s something even more impressive, as the iPhone 5S can shoot at 10fps, full resolution for as long as you’ve got spare storage space. We hit more than 200 pictures at the phone showed no sign of slowing down.

Burst mode pictures are marked separately in the Photos app and aren’t saved to iCloud by default. When you open a burst collection the iPhone automatically chooses which ones it thinks are the best shots, although you can easily select other shots instead. Marked shots are then saved to the phone independently and uploaded to iCloud. With your favourites stored, you can delete entire burst collections in one go, so your phone won’t get cluttered with shots.

Thanks to iOS 7 there are now more filters available on the phone, so you can switch to black and white, sepia, amongst others, when you take a shot. Filters are non-destructive (copy the images off the phone via USB and you’ll get the original image), so you can remove a filter at a later date or add one to a normal photo instead. The same goes for the square mode pictures, which are non-destructive crops of the original image, so you can recover the full frame if you want.

Panoramas are still as impressive as when they were introduced with the iPhone 5. Just turn on the spot while holding the phone steady using the online guide and the images are stitched together practically as quickly as you can move.

iPhone 5S review: HD Video

It’s the video camera that’s had the biggest overhaul thanks to the A7’s image processor. As well as shooting 1080p video, which looks great, even in low-light thanks to the new sensor, it has a brand-new Slo-Mo mode, which shoots 720p at 120fps. When played back at the regular 30fps, you get stunning slow motion.

Slow-motion is becoming more popular with the latest high-end smartphones, but it’s still just as impressive on the iPhone 5S. What makes the mode a joy to use is the simple built-in editing tools, which uses simple sliders to set which part of the video you want to play back at full speed. It’s super easy to use and you can bash out a home video that Zack Snyder would be proud off in seconds. As you can see from the example below, the quality really is amazing.

Raw video footage pulled off the phone via USB is just at 120fps, so if you want to keep the slow-motion portion of the video, you need to share the video, such as by uploading to YouTube, or make sure it’s backed up to iCloud.

Note that if you transfer a slow-motion video to another iOS device using AirDrop, such as an iPad, the video is compressed fixing where the slow-motion part is. If you want to edit on another device, make sure you use the slider controls to remove the slow-motion part, so the video is transferred in its complete 120fps mode.

As we said, regular video doesn’t suffer at all and is shot at 30fps at a resolution of 1,920×1,080. Thanks to the new sensor having larger pixels, it means that footage is cleaner, particularly in low-light, when compared to the iPhone 5. As you can see in the example shot below, taken from the full video, when in relatively low light, the image is still detailed, colours are good and there’s very little noise, either.

To see the camera in action with the actual footage, you can play the YouTube video below, which shows how the camera deals with a dimly lit scene, a darkly-lit scene and a brightly-lit scene.

iPhone 5S review: Verdict

Since the iPhone 5S came out, there’s been some stiff competition from other Android phones, but there’s still a lot to love about this handset, even if it’s several years old. It’s no longer the best tiny iPhone – that honour goes to the much more up to date iPhone SE – but if you’re desperate for an iPhone that doesn’t cost a lot, then the iPhone 5S is more or less your only option.

It’s neat, easy to use one-handed and slips neatly into any pocket. Performance wise, the iPhone 5S still stands up well and it’s aged very well. However, if price and size aren’t as important and it’s a pure decision of whether to get this or a newer iPhone 6S, we’d advise that you buy the 6S. This larger handset looks better, has a better screen, better camera and a faster processor. It may be more expensive, but it certainly feels like the more modern phone. Read our iPhone 5S vs iPhone 6 vs iPhone 6S comparison for more information.