Just how good is the camera in the iPhone 6S and iPhone 6S Plus? To find out, we spent a day with professional photographer and videographer Dan Pearce, who bought his iPhone 6S Plus on its very first day on sale. We also took along an iPhone 6 Plus to shoot direct comparisons, and the results are fascinating.
Dan didn't just shoot stills. He also tested the iPhone 6S's 4K video capabilities and its Slo-mo mode – this was a chance to see what a video expert could do with the iPhone's camera.
The iPhone 6S also has a much better 5-megapixel front camera compared to the lowly 1.2-megapixel FaceTime camera in the iPhone 6. We'll look at this some other time, though – here, were concentrating on the rear camera, the one you'll use for everyday photography.
The iPhone camera has long had a reputation for being the best there is in a smartphone, even though its resolution falls some way short of its rivals.
The new iPhone 6S brings an increase in resolution – the first for some time – but only from 8 million pixels to 12. The camera in the Sony Xperia Z5 has 23 million pixels, the Samsung S6 has 16 million pixels and so does the LG G4.
But this isn't a camera comparison between the iPhone 6S, Xperia Z5, Samsung S6 and LG G4. This is an assessment of the iPhone 6S camera for photographers as a proper photographic tool, compared with other regular cameras.
It's not just about the resolution
The photography world has long since realised that megapixels on their own don't guarantee image quality. In fact, cramming more and more megapixels into small sensors (small enough to fit in a smartphone) has the opposite effect. Detail rendition may improve, with the right sort of subject, but digital noise increases and more aggressive noise reduction is needed to control it. The result – too often – is a 'watercolour' effect in fine detail and smoothing over of subtle textures. You see this a lot in high-megapixel point and shoot digital cameras, too.
Outright resolution is certainly not the only thing to look for in a camera. Despite its relatively low megapixel rating, the old 8Mp iSight camera had plenty of megapixels for online use and even moderate-size prints, and the new 12Mp camera in the iPhone 6S should be capable of bigger blow-ups. To put this in perspective, a full-bleed, full-page image in a magazine needs only 6-8 million pixels.
There's a lot more to it than that, though. Photographers will also look for high dynamic range – the ability to hold on to detail even in brightest parts of a picture – and the iPhone camera's automatic HDR mode has proved itself very effective at this in the past, combining separate exposures in an instant to extend the brightness range it can capture.
Photographers also want freedom from aberrations, including distortion (the bowing of straight lines towards the edges of the picture), chromatic aberration (color fringing around object outlines) and edge softness (where the lens's resolving power drops off towards the edges of the picture). Whether it's down to lens quality, clever image processing or both, the iPhone's existing 8Mp iSight camera practically eliminates all three of these troublesome image flaws.
The iPhone camera app pulls off a similar trick, appearing basic on the surface but proving capable of great results and unexpected levels of control. There are plenty of other really good camera apps to choose from with more features and a wider range of filters, but we've concentrated on the built-in camera app to show what it can do.
The Auto HDR function is just one of its features. It also has an LED flash which can be used to illuminate subjects in the dark, though only at close range, and which produces a warmer, slightly softer light than the cold, harsh flash units in compact cameras.
It's possible to set the focus and exposure for one particular part of the scene by tapping on the screen, and you can tap and hold to lock the exposure and focus completely, even for a series of shots.
The standard Photo mode shoots 12Mp images in a 4:3 aspect ratio, but there's also a Square mode for Instagram style shots, and a set of eight effects filters for creating anything from a black and white 'Noir' effect to retro-style fade, instant film transfer and cross process effects. Or you can shoot in the super-wide Pano mode, capturing wide vistas with a single sweeping movement of the phone.
And it would be easy to overlook the new Live Photo option built into the Photo mode. This captures a regular still image, but also captures around two seconds of moving images before and after you tap the shutter release. These are shot at 15 frames per second and saved as a movie file alongside the still image – and when you press and hold the image thumbnail on the iPhone 6S using the new 3D Touch gesture, the still image comes to life in a way that really does add a new dimension to snapshots.
The video features sound equally impressive, but can a smartphone really shoot good-quality 4K video without stuttering and compression artefacts? And can the iPhone 6S really shoot smooth slow-motion 720p HD video at 240fps? Sony's brand new A7S II 4K-dedicated compact sytem camera can only achieve half that frame rate at the same resolution. We wouldn't expect the iPhone to match the Sony's quality, but that's still an indication of the video processing power crammed into the iPhone 6S.
We have an entire page dedicated to the iPhone 6S's video capabilities, but here's a quick taster. For this and subsequent videos, you'll need to choose the maximum YouTube resolution – the default playback resolution is much lower than the iPhone's.
On the surface, the iPhone 6S camera app is really simple to use. You can just point it at the subject you want to photograph, tap the shutter button and it takes the picture – it takes care of both the focusing and exposure automatically, recognizing any faces in the scene and using the HDR mode if the brightness range in the scene is too high for the camera to capture with a regular exposure.
There is one obvious limitation compared to a regular digital camera – there's no zoom. You can use a digital zoom function, but this simply blows up a smaller area of the picture, sacrificing pixels and resolution. We wouldn't recommend digital zoom on any camera.
So you can't zoom in optically on objects which are further away – the only way to make them bigger is to get closer (long ago, almost all photographs were shot this way…). This feels like a major restriction at first – it certainly rules out any kind of long-distance sports or wildlife photography – but after a while you adapt, and you start to notice that in some ways it's a very liberating thing. There's less to think about when you're taking pictures, leaving you free to concentrate on what you're photographing. iPhone photography is spontaneous and instinctive. It makes you explore and interact with your subjects much more closely, which often yields photographs and angles you wouldn't have thought of before.
The other restriction is that there are no manual controls for exposure or focus, two of the first things you'd look for in any kind of serious camera. There are, however, features which achieve practically the same thing.
Focus and exposure adjustment
First, you can simply tap anywhere on the screen to lock the focus and exposure at that point – it's like spot metering and manual focus point selection rolled into one (there are third-party camera apps which can separate the focus and exposure points so that you can set them individually).
It goes even further than that, though. Alongside the focus/exposure box is an exposure compensation slider – you can drag up and down on the screen (you don't have to drag on the slider gadget itself, dragging anywhere on the screen will do) to increase or reduce the exposure level. This is especially useful if you're shooting intrinsically light or dark subjects, which tend to fool any light metering system.
The camera app goes further than this, though. If you tap and hold, the camera applies an AE/AF lock function that persists even after you've taken the picture and you're lining up the next. It's a way of fixing the focus and exposure across a whole series of pictures, which can be really useful if the background is changing, say, but the lighting on your subject is staying the same.
This AE/AF lock function doesn't just work in the Photo mode. You can also use it in the Pano and video modes, and this is where you start to see its real potential.
There is a conspicuous lack of any reference to white balance. The camera does a good job of correcting the colours in a range of outdoor and indoor lighting conditions, but you have no direct control over the setting. It does appear to be locked at the same time as the focus and exposure settings, however.
So one way or another it's not difficult to get shots looking just how you want them – and the iPhone does produce a really good hit-rate of technically successful pictures.
But how good is the new 12-megapixel camera and is the detail rendition visibly better than the old 8-megapixel model?
That depends on the subject. Apple hasn't just changed the sensor, it's changed the processing too. It's clear from studying many different images that there's more noise reduction and more sharpening with the new camera. High-contrast detail like lettering does stand out more clearly with the new camera, but fine textures look no better and, in fact, at higher ISOs, fine textures start to get smoothed over.
This is typical of how makers handle small, high-resolution sensors, and it does feel like a backward step. The differences are small and subtle, though, and judged in isolation the iPhone 6S's images are sharp, colorful and detailed.
Where it really scores over a typical point and shoot compact camera is the total absence of aberrations. Images are sharp right to the edges, there's no color fringing and straight lines stay straight, even at the edges of the frame.
Presumably there's a good deal of behind-the-scenes processing going on to achieve these results, but the fact remains that there are high-end compacts and even DSLRs that can't match this degree of optical correction.
The HDR mode is also very impressive. You can switch it on and off, but it's best left set to Auto so that the camera can decide when to use it. Its effect is most noticeable in outdoor scenes with bright skies – the HDR mode holds on to rich detail in skies that would otherwise blow out completely. It also does this while producing perfectly natural-looking results.
It doesn't always work perfectly, though. It's fine where everything is in focus because it relies on finding hard edges to transition from one exposure level to another. If you've got out-of-focus areas, however, it goes a bit wrong, because it creates a hard boundary right in the middle of a soft outline and it sticks out like a sore thumb.
Low light performance
We tested the iPhone 6S Plus in the lowest light we could find, in an unlit passageway in a derelict brick warehouse. Even then, we couldn't persuade the iPhone to go higher than ISO 400. It uses the light-gathering power of its f/2.2 lens and its highly effective image stabilizer to stave off ISO increases for as long as possible. In our tests, it was prepared to go to a shutter speed as low as 1/4sec before increasing the ISO – but the stabilization system in Dan's 6S did still produce a sharp image. It would have been interesting to repeat this test with the regular iPhone 6S (not the Plus), because that doesn't have an optical image stabilizer.
It is clear that Apple has increased the noise reduction at higher ISOs. The iPhone 6S shows little noise at ISO 400 but visible image smoothing. This is in contrast to the iPhone 6, which produces more noise but also a finer detail rendition. Most photographers would probably prefer the latter.
In general, though, the iPhone 6S is very good in low light – mostly because the f2.2 lens lets in enough light that the camera can postpone increasing the ISO sensitivity until the lighting conditions are very dim indeed.
The iPhone 6S is quite prone to lens flare – like the iPhone 6 before it. If you're shooting into the light you can expect your images to show some loss of contrast and, if the sun is near or just inside the edge of the frame, you'll get much stronger lens flare effects, with streaks of light or circular reflections of the lens elements.
Autofocus speed and Live Photos
One area where the new iPhone 6S is definitely improved is the autofocus speed. On average, the 6S felt like it focused twice as fast as the iPhone 6, which made picture-taking feel more immediate and spontaneous.
The Live Photos mode is particularly easy to use, mostly because it's on by default and the camera doesn't behave differently in any way. In theory, then, any photo you take will come to life when you press and hold the thumbnail.
In practice, you have to take Live Photos differently, allowing for a couple of seconds either side of the 'still' image to capture the moving pictures. Initially, most of your Live Photos will end with shots of your feet because the first thing you do (usually) is lower the camera to look at the picture.
You can just ignore the 'live' element altogether and just shoot and view your pictures as stills – though the animated element does soak up extra storage space on your device.
Square mode, filters and the Photos app
The Photo mode is not the only way to shoot images. Retro fans should also try out the Square mode which, as the name suggests, shoots square image rather than rectangular ones. The retro connection is the old 6 x 6cm twin-lens reflex and other medium format film cameras which took 12 (or 24) square images on a roll of film.
The advantage back then was that you didn't have to rotate the image through 90 degrees to take a portrait format shot – far from easy with a cumbersome medium format camera. The intention of the square format was, partly, so that you could crop the image horizontally or vertically later on, according to how you wanted to use it. But square images also have an aesthetic appeal of their own, forcing you into seeing and composing images in a new way.
Instagram fans will be used to shooting in the square format because it's only recently that other aspect ratios have been introduced. Meanwhile, the rest of the photo-sharing industry seems to have adopted the convention of displaying image thumbnails as squares, even when the originals are rectangular.
The thing to note about the Square mode on the iPhone is that there's no going back. You can change your mind later about the photo filters (which we'll come to in a moment), but if you take a picture in the Square mode, it stays square for good – you can't 'uncrop' it later on to get back to a full size image.
The other point is that you are sacrificing some of the camera's megapixels – the iPhone 6's 8-megapixel sensor goes down to 6 megapixels, while the 6S drops from 12 megapixels to just over 9 megapixels.
The big advantage, apart from the retro appeal, is that you don't have to rotate the camera to take the shot. It's much more comfortable to hold the iPhone vertically than horizontally, your grip is much more secure and you're not going to leave your finger over the lens by mistake.
You can use the iPhone's effects filters in both Photo and Square mode, and you choose them by first tapping the button in the bottom right corner of the screen, then by tapping on whichever of the preset effects you like the look of in the grid – the great thing is that they all display a live rendition of the scene you're photographing. The central filter in the 3 x 3 grid is 'None' – tap this if you want to remove any existing effect.
You might be tempted to write these filter effects off as unwanted novelties, but they are worth a look, especially as you can change your mind later (more on this shortly). The Noir filter gives a high-contrast black and white effect with dramatically darkened skies, while the Chrome filter gives the supersaturated, high-contrast appearance of old-fashioned slide film.
So let's say you use the Chrome effect and then wish you'd chosen the Instant effect instead. You can tap on your picture in the Photos app, tap the Edit button, tap the Filters icon at the bottom and simply choose a different filter.
They are completely non-destructive. The iPhone captures the original, unfiltered image (in fact this is all you see if you copy it to a computer) and your filter choice is simply a processing instruction stored alongside it, and one which can be changed at any time.
This applies to all the editing tools in the Photos app. Whatever you do to your image, whether you crop it, change the exposure and colors or even convert it to black and white, you can go back and change everything you've done. The changes you make are visible across all your devices if you use the iCloud photo library, but they're not applied permantly to the photo. The only way to make a permanent version is to send the picture to someone else in a message or email (or to yourself if you want to make a processed copy of the original).
The Pano (panoramic) mode is particularly interesting. Lots of cameras now use the same 'sweep panorama' action, but on the iPhone 6S it works particularly well.
First, you shoot with the iPhone held vertically. This might seem odd at first, but this gives you a wider angle of view vertically – the horizontal angle of view is determined by how far you pan the camera.
The iPhone displays an arrow on a horizontal line, and as you pan the camera you need to keep the arrow on the line – or as close to it as possible. This keeps your panorama level and reduces the amount of the image lost to cropping when the iPhone cleans up the edges.
By default, you pan from the left to right but you can reverse the direction by tapping on the arrow.
Once you've worked out the composition, you start the panorama by tapping the shutter button. You then sweep across the scene smoothly, keeping the arrow on the line, and then tap the shutter button again when you want to stop.
At first, it's tempting to shoot the widest panoramas possible – but these extreme letterbox shapes are difficult to view and often oddly uninteresting. It's much better to use a shorter sweeping movement to capture a narrower angle of view and a more normal aspect ratio. The trick lies in knowing when to stop and in looking for effective compositions, rather than just shooting the widest view possible.
The other issue with extra-wide panoramas is that objects directly in front of you, such as buildings or the line of surf on a beach, can appear to 'bow' towards the camera. This isn't a fault – it's simple geometric distortion. This is another reason to keep your panning movements relatively short.
The wider view
In fact, the Pano mode is such a handy way of shooting a wider than usual view that you can find yourself using it a lot. The sweeping movement hardly takes any longer than lining up a regular photo and the stitching is so effective that you can rarely see the join.
You do have to watch out for objects and people moving in the foreground, though – they can be chopped in half or distorted in unexpected ways. It's something to check when you've used the Pano mode, just in case you need to take the shot again.
You can't apply any of the iPhone's effects filters when you shoot a Pano image, but you can apply one later using the Edit mode in the Photos app.
One potential issue with panoramas is exposure. Normally, the phone locks the exposure and focus on the first frame, and if this is shooting into the sun or dark shade it's going to upset the exposure for the rest – but you can frame up the shot with the most important area in the frame, tap and hold to lock focus and exposure and this will stay locked while you reframe and shoot your panoramic sequence.
The iPhone's camera has a focal length equivalent to 29mm, so it has a pretty wide angle of view already, but sometimes even this isn't wide enough to capture what's in front of the camera, so the Pano mode is a quick and simple way to extend your iPhone's angle of view.
4K video and Slo-mo mode
It's hard to take video modes on phones seriously. Cameras that take professional-quality video cost thousands, and regular consumer cameras don't tend to match the video quality even if the specs seem similar. If you've used the video modes on point-and-shoot compact cameras, you're going to be expecting the worst.
So the iPhone 6S video specs sound wildly ambitious – good-quality 4K video on a mobile phone? Really? Even more outlandish is the Slo-mo mode, which can – allegedly – shoot standard 720p HD video at an amazing 240fps. Played back at 30fps, that gives you an 8x reduction in speed.
The 4K is fantastic
One of the reasons for getting a video expert like Dan on board is that he knows how to use a camera so that you're only revealing any faults in the camera's performance, not in the operator's technique.
And Dan had high praise for both the detail rendition – we watched 4K video played back at 100% magnification on a computer screen – and for the way it handled movement. This clip (above) really shows the level of detail the 6S can capture, and the lack of compression artefacts and texture smoothing in the stone fountain.
Cheap consumer cameras often blur fine detail with heavy inter-frame compression, but the iPhone's 4K footage is really clean, sharp and stutter free. If you do see stuttering, that's more likely to be caused by what you're playing it on – relatively few computers have the graphics power needed to play back 4K video smoothly.
Here's another example of the iPhone 6S's 4K video quality. The autofocus can't quite keep up with the spider as the wind blows the web to and fro – that would be a lot to ask of any camera – but when it snaps into focus the level of detail is very high. The second video, directly below is a 1080 full HD crop from the 4K version. Remember this is now just one-quarter of the 4K image area captured.
The iPhone doesn't always get it right. In the video of the swans, above, it starts off well, but the sudden switch to a darker background mid-way through makes it over-expose the swans badly. The solution, however, would be to set the AE/AF Lock before filming.
In this clip you can see the effect of the lack of shutter speed control. The shutter speed is quite high, even in these shady conditions, which makes the movement of the dogs look slightly less smooth than it should.
You might not see the need for 4K video now, but in the future when 4K devices are everywhere, you may be glad you shot it. But if you do plan on shooting 4K footage, don't even think about getting a 16Gb iPhone 6S – 4K video takes up almost three times the space of 1080, and you'll fill up the phone's memory in minutes.
It's true that even the screen on an iPhone 6S Plus is only 1080 resolution, but don't forget you can pinch to zoom even during video playback, and this is where the sheer level of detail in the 4K footage becomes apparent.
If the 4K video is impressive, the Slo-mo mode is better still. 240fps footage played back at 30fps is amazingly smooth and detailed, and the iPhone has a neat playback trick, where the first couple of seconds are played at normal speed and then it shifts down into slo-mo mode. For the final couple of seconds it shifts back up to normal speed again. This gives a really nice effect, like a properly edited movie rather than a straight slow-motion clip.
Interestingly, when you play these Slo-mo movies back on a computer, you don't get this speed change – the movie is in slow motion throughout. The speed changes are applied by the iPhone and not baked into the video.
In fact, you can open a Slo-mo movie, tap the Edit button and change the points at which the playback speed changes. You can also trim the ends of Slo-mo movies (and regular movies) and export trimmed movies as new video clips.
The Slo-Mo version of our fountain video is captured at a resolution of 1280 x 720, which is really impressive given the frame rate – but you can see a lot more texture smoothing in the stonework of the fountain, indicating higher levels of compression.
Here's one unexpected thing – the Slo-mo mode also records audio. In our slo-mo shot of a fountain, you can hear the water trickling. Things get weird with human speech, which slows into a kind of menacing subterranean growl, but it adds to the fun and it's way better than having no sound at all.
In lower light levels, Slo-mo movies can lose a little crispness, but the 6S should get due credit for being able to shoot 720 movies at 240fps in the first place.
The Time-lapse mode is fun, but fairly limited. The idea is that you capture a series of still images in real time and the camera turns them into a movie played back at a higher speed. It works fine – a stylised stopwatch spins round ticking off markings around the dial (each one is another frame) until you tap the button to stop. You then see a speeded-up movie made out of the individual frames.
You could use it handheld for a kind of first-person movie, or you could use a phone clamp and a tripod to record a sunset or a busy city street at night, say.
iPhone 6S Plus vs iPhone 6 Plus
Throughout our photo expedition we shot the same subjects with both Dan's iPhone 6S Plus and our own 6 Plus. At first glance it was quite hard to tell the two sets of images apart – Apple has kept the exposure levels, colours and tonal rendition exactly the same, which is a good technical achievement considering that the camera is new. If you're completely tuned into the way an iPhone camera works, the one in the 6S will deliver exactly the results you're used to.
But closer inspection of the images revealed some interesting differences, and we've already mentioned this in earlier sections. Apple has changed not only the sensor resolution but also the image processing and, regrettably, it's done what a lot of camera makers do – it's gone for heavier noise reduction and increased sharpening.
The new camera can resolve certain types of detail better than the old one. Anything which hard, clear edges, such as lettering or signs, is rendered more clearly. But it can't quite record fine, subtle textures as well as the old 8-megapixel iSight camera. This becomes more obvious at higher ISO settings, where the old camera shows more noise but also more detail. The new 12-megapixel camera has the noise smoothed out but, as is usually the case with noise reduction, some of the fine textural detail goes with it.
Check out our comparisons below to see what we mean.
The camera in the iPhone 6S has all the qualities that mobile photographers have come to admire in the old 8-megapixel iSight camera. Images are bright, colorful and clean, and even though the megapixel count is modest, it makes up for it with consistently sharp detail rendition, both in the center of the frame and right out to the edges.
The images are also free of distortion and chromatic aberration, the twin scourges of cheap (and not so cheap) camera lenses. We suspect these aberrations are being corrected during the image processing phase, but that hardly matters because the results are excellent and leave no sign that they've been corrected digitally.
This camera might have only 12 million pixels, but each one is used to its absolute best. Most cameras are limited by their lenses and/or the way the images are processed, rendering their sensor resolution a little academic. This one is not.
Is the iPhone 6S better than a regular point-and-shot digital camera? Except for the fact that you don't get a zoom lens, definitely. Is it a match for a DSLR or a compact system camera? No. But it is good enough for serious photographers who've left their DSLR/CSC at home to shoot with confidence, knowing that the images captured with the 6S will stand up in their own right.
The iPhone 6S camera is simple to use and delivers excellent results. The Pano mode is so quick, straightforward and effective that you can use it for super-wide snapshots with hardly more effort than taking a regular photo. The real revelation, though, is the quality of the 4K video and Slo-mo modes.
The old 8-megapixel iSight camera delivers extremely good fine, textural detail for a small-sensor camera. The cost is a faint noise pattern, usually barely visible, but there nonetheless. Most photographers, however, would happily accept faint noise in exchange for this detail rendition. Disappointingly, with the new camera Apple has opted for increased noise reduction and increased sharpening (probably to offset its effects). As a result, the new camera's images look a little more 'processed' when you examine them up close, and the jump from 8 megapixels to 12 hasn't delivered a proportional improvement in detail rendition.
Mild disappointment about the image processing aside, this is a great camera in all senses – regardless of the fact that it's in a phone. Keen photographers will be rightly suspicious of any small-sensor camera, but this shows small sensors can nevertheless deliver real quality.
Of course, we now have to carry out the same tests with the iPhone's rivals, the Sony Xperia Z5, Samsung Galaxy S6 and LG G4. Interestingly, these beat the old 8-megapixel iPhone in our lab tests, but real-world results are a different thing again, and this is where the iSight camera really impresses.
This extended test was designed to find out whether the new 12-megapixel iSight camera is better than the older 8-megapixel camera for still images (hmm… maybe), whether a mobile phone can really shoot top quality 4K video (amazingly, yes) and whether the iPhone is a genuine photographic tool for serious photographers (definitely).
iPhone/mobile photography isn't just a cheap and cheerful fallback for when you've left your proper camera at home – it's a serious photographic movement attracting both photo enthusiasts and artists. Mobile phone photography hits the 'reset' button in a photographer's brain. Its limitations and its opportunities make you see, shoot and share images in a whole new way.