The Apple iPhone 6s and iPhone 6s Plus Review
by Ryan Smith & Joshua Ho on November 2, 2015 8:00 AM EST- Posted in
- Smartphones
- Apple
- Mobile
- SoCs
- iPhone 6s
- iPhone 6s Plus
Camera Architecture
As usual, it’s important to discuss some of the basics of the camera hardware before we move on to actual image and video quality tests in order to better understand the factors that can affect overall camera quality. Of course, there’s much more to this than meets the eye but for the most part things like the actual lenses used are hard to determine without a device teardown.
| Apple iPhone Cameras | ||||
| Apple iPhone 6 Apple iPhone 6 Plus |
Apple iPhone 6s Apple iPhone 6s Plus |
|||
| Front Camera | 1.2MP | 5.0MP | ||
| Front Camera - Sensor | ? (1.9 µm, 1/5") |
? (1.12 µm, 1/5") |
||
| Front Camera - Focal Length | 2.65mm (31mm eff) | 2.65mm (31mm eff) | ||
| Front Camera - Max Aperture | F/2.2 | F/2.2 | ||
| Rear Camera | 8MP | 12MP | ||
| Rear Camera - Sensor | Sony ??? (1.5 µm, 1/3") |
Sony ??? (1.22 µm, 1/3") |
||
| Rear Camera - Focal Length | 4.15mm (29mm eff) | 4.15mm (29mm eff) | ||
| Rear Camera - Max Aperture | F/2.2 | F/2.2 | ||
At a high level, not a whole lot changes between the iPhone 6s and iPhone 6. The aperture remains constant, as does the focal length. Sensor size is also pretty much unchanged from the iPhone 6 line. Unfortunately, the iPhone 6s continues the trend of not having OIS, which has significant effects on low light photo and all video recording. Of course, OIS alone isn’t going to make or break a camera, but it can make the difference between a competitive camera and a class-leading one.
I’m sure some are wondering why the aperture hasn’t gotten wider or why the sensor hasn’t gotten larger, and it’s likely that attempting to make a wider aperture or a larger sensor would have some significant knock-on effects. A wider aperture inherently means that distortions get worse, as even in simple cases like chromatic aberration the incoming light is now reaching the lenses at a more extreme angle. A larger sensor with all else equal would significantly increase thickness, which is already near acceptable limits for the iPhone 6s camera module. Even if you modified the lens design to focus on z-height, the end result is that the focal length is shortened significantly. Even if you don’t think a wider field of view is a problem, distortion throughout the photo increases which is likely to be unacceptable as well.
In effect, the major changes here are pixel size/resolution and the ISP, which is a black box but is new for the A9 SoCs as far as I can tell. Instead of the 1.5 micron pixel size we’ve seen before, Apple has moved to a 1.22 micron pixel size for the iPhone 6s and 6s Plus. There’s been a perennial debate about what the “right” pixel size is, and some of the research I’ve done really indicates that this changes with technology. For the most part, noise from photos taken with strong, even lighting is solely due to the fact that light is composed of discrete photons. This shot noise is an unavoidable fact of life, but in low light the problem is that the sensor’s inherent noise becomes noticeable which is affected by factors like the sensor die temperature. The problem here is that in CMOS sensors each pixel has circuitry which independently converts the number of electrons counted into a corresponding voltage, which means that for the same sensor size, if you increase the number of pixels you’re also increasing the amount of read noise.
As a result, while in theory a smaller pixel size (up to a certain limit) has no downsides, in practice due to the way CMOS image sensors are made you have to trade-off between daytime and low light image quality. Apple claims that their way of avoiding this trade-off is through the use of new technology. One of the key changes made here is deep trench isolation, which we’ve seen in sensors like Samsung’s ISOCELL. This basically helps with effects like electron tunneling which causes a photon that hits one sensor to be detected at another. The iPhone 6s’ image sensor also has modifications to the color filter array which are designed to reduce sensor thickness requirements by increasing the chief ray angle.
Camera UX
Moving on to the camera UI, iOS has basically kept the same UI that we’ve seen since iOS 7. There’s nothing that I really have to complain about given the relative simplicity and the lack of any notable usability issues here. The one major change I’ll mention here is the Live Photos button, which illuminates and indicates when the camera is capturing a live photo. The one usability problem worth noting here is that the camera doesn’t stop capturing a live photo even when the camera is lowered, so live photos often just show the ground or some fingers towards the end. Otherwise, the experience is exactly like a normal photo.
Other than the addition of the live photos button, there are some subtle additions to the camera UI due to the addition of 3D Touch. Peeking on the image shows the last 20 images captured on the phone, and popping will open up the gallery in an interesting dark theme mode which is slightly odd and inconsistent but otherwise a nice addition. A force touch on the camera app icon allows quick access to some common modes without extra actions after opening the camera application.
Of course, the other question that still lingers is how fast the iPhone camera is. In order to test this, we continue to use our ISO chart with strong studio lighting in order to get an idea for what the best case focus and capture latency are. As the ISO chart is an extremely high-contrast object, this test avoids unnecessarily favoring phase-detect auto focus and laser AF mechanisms relative to traditional contrast-detect focusing.
When it comes to focus latency, the iPhone 6s is basically identical to the iPhone 6. At this point, we're basically looking at variance in testing as a 64ms difference is only 4 frames on the display. Something as simple as a small difference in initial focus position is going to affect the result here, because the iPhone 6s traverses straight to the correct focus position in testing. Pretty much every other smartphone is behind here because they all seem to traverse past the correct focus point before reverting to verify that PDAF or laser AF is giving an accurate result.
In the shot latency test, we're really seeing the value of Apple's NVMe mobile NAND solution here as the iPhone 6s captures a single image in roughly 200 ms less time than the iPhone 6. Of course, this is assuming a situation in which shutter speed isn't the dominating factor in shot latency so in low light these differences are going to be hard to spot.
Live Photos
Live Photos is a new feature in the iPhone 6s, which is effectively trying to capture a moment within a photo. At a technical level, Live Photos captures a photo and a video simultaneously, with the video lasting up to three seconds. The first half of the video is going to be the moment immediately before the shutter is tapped, and the second half is right after the shutter is tapped. The video has a resolution of 1440x1080 to fit the 4:3 aspect ratio, and appears to vary in frame rate from about 12 to 15 FPS, with a bitrate of roughly 8Mbps and H.264 high profile encoding.
These are all technical details, but really what matters here is that the frame rate is relatively low so it isn’t necessarily the greatest at capturing something that is going to pass through the frame within a second. It’s likely that this is at least partially necessarily in order to make sure that Live Photos don’t take up a huge amount of storage. Similarly, I suspect this is the same logic behind why the resolution is closer to a video than a photo. The frame rate is low enough though that low light photos aren’t going to be limited by the need to keep the video at an acceptable frame rate. This is important to note, mostly because the whole point of a live photo is kind of ruined if you have to turn it on to use it.
Ultimately, with these features it is insufficient to focus on the technical details of the implementation, even if they matter. What really matters here is the user experience, and to that end Live Photos solves a lot of the friction that was present with HTC’s Zoes. I loved the idea of Zoes when I first got the HTC One M7, but after a few months I found I just wasn’t using the feature because it was too much effort to try and pre-emptively plan for a shot that would work well as a Zoe. It was also difficult to deal with the fixed recording time, a higher minimum shutter speed in low light, and the need to keep the phone raised for the entire time the Zoe was recording.
In some ways, Apple has solved these problems with Live Photos. It’s fully possible to keep the mode enabled all the time, and with the recent release of iOS 9.1 it seems Apple has implemented an algorithm to dynamically alter the length of recording based upon whether the camera is suddenly lowered in the middle of recording. Due to the relatively low frame rate there’s also no need to worry about worse low light performance or something similar, which helps with keeping the feature enabled all the time even if it means that motion isn’t has fluent as it would be with a 30 or 60 FPS video. The end result is that you can basically just take photos like usual and serendipitously discover that it resulted in a great live photo.
I really like the idea of Live Photos, and in practice I had a lot of fun playing with the feature to capture various shots to see the results. Even though I’ve spent plenty of time with the iPhone 6s I still don’t know whether I’ll actually continue using the feature in any real capacity as I definitely used HTC’s Zoe feature for the first few weeks that I spent with the One M7 but as time went on I promptly forgot that it ever existed.
Facebook
Twitter
RSS
531 Comments
View All Comments
nerd1 - Saturday, November 7, 2015 - link
720p screen in 2015, worse battery life, no sd slot, no wiress charging, terrible camera and still THE BEST phone huh?It has best performing processor, no one argues that, but I still wont touch it with a stick.
JaytB1 - Sunday, November 8, 2015 - link
I use iPhone mainly because of the better security/privacy, no carrier/manufacturer delay/total dismissal of security/OS updates, earlier/exclusive/better releases of triple A games/apps and uncluttered interface. I agree with the gold award, the iPhone 6s (plus) is the first phone in a while that made me see that there are still possibilities to innovate in the smartphone space.I've seen Android users avidly defending their high PPI's, megapixels, core counts. Oh, but it's customizable and I can put a ton of widgets on my homescreens. There's only a small minority of tech obsessed people who care (proof is in the huge low/medium end market share, indicating the amount who don't care for specs but just want a working phone). For me, all I want is to launch an app, not stare at my home screen. In the past, Android users where more often than not boasting about benchmarks and how their hardware was superior. Now that the tables are turned, hardware all of a sudden doesn't matter as much anymore or the tests must be rigged by a biased Anandtech (who has nothing to gain and everything to loose if they were posting nonsense).
I've seen Samsung and other manufactures add so many gimmicks to their phones, many of which are plain impractical (try doing 'airview' while jogging and you'll get the picture).
I admit that fast charging would be nice but, for me, completely unnecessary (it's not like an iPhone charges slow in the first place).
Then there's wireless charging, you do realize that you still have to plug in the charge pad with a cable right? So the only difference is that you don't need to plug that cable into your phone, but you'll need more power to fill your device up as compared to using a cable (more waste power) and a permanent spot for your charging pad. Again, for me I don't really see the appeal for that either.
We could also talk about PPI but to keep it brief, I'd rather have a device perform well with individual pixels I can't distinguish, than a screen that would impact performance with pixels I still can't see... But more of them.
I could go on about how a blind photo evaluation test on a respected Android site had Android users voting the iPhone 6s as having the best overall picture quality, but now that the iPhone scored a tiny bit lower than some Android phones in one test, it suddenly has a 'far inferior' camera. Then there's the RAM, curved screens and so many other things I could mention, but my point is that I think Android users can't recognize a genuine game-changing feature-list because they're so used to getting bombarded by tons of arguably useless high spec lists and gimmicks that are marketed as 'the next big thing'.
It's almost as if Google took over the reality distortion field from Apple. Just wait a couple of years when all Android devices have 'Android sense' (or something) displays (3D touch), THEN it will be a game changing feature because they'll have 1000's of pressure levels they can sense as compared to the 'useless' iPhone's (hypothetical) 128 levels.
Don't get me wrong here, I'm not trying to bash Android or people who choose to use it, I just don't like those who post nonsense without anything to back it up just so they can sleep at night having convinced themselves that they bought the right phone. I've been a reader of this site for years and believe their test results to be correct, as they've always been. People who claim otherwise should come with facts or stop sprouting nonsense.
I, for one, agree with the review and think it's the phone with the best all round feature set on the market today. Is it perfect? Of course not, but it's a genuinely forward thinking and exceptional smartphone in a stale smartphone market, and that deserves that gold award in my book.
Thanks for the review!
Aritra Ghatak - Sunday, November 8, 2015 - link
As the reviewers pointed various aberration and distortions associated with using a brighter lens and that it is wise Apple went with the F 1/2.2 aperture lens. Could you please explain how Samsung manages with an F 1/1.9 aperture lens in Galaxy S6? Or for that matter the F 1/1.8 lens in LG G4 or Nokia Lumia 720/730?patamat - Sunday, November 8, 2015 - link
Well, we all know who Anand went to work for after writing few "balanced" reviews like this one.(apple ...)
Psymac - Monday, November 9, 2015 - link
Where is the phone function analysis of this iPhone?zimmybz - Tuesday, November 10, 2015 - link
I guess I'll try to build the bridge for the Droid guys here that are having a hard time.I haven't had an iPhone since the Galaxy S came out. Been a droid user since.
I recently got a 6S Plus. I sold a Note 5 and cancelled a pre-order for a Nexus 6P.
I will say it since nobody else will. The Note 5 has a great camera, S-Pen is cool, and enough RAM to keep multi-tasking running, but otherwise it's a shitty phone. The battery life and Touchwiz still leave a LOT to be desired. Build quality is great, but it suffers from what every other Droid phone suffers from - fractured, fragmented hardware eco-system and specs driven production. (Hang on)
If you need to know why you should cancel a 6P pre-order, look at the subreddit (Holy crap, lol.)
Anyways, in my first week with the 6S Plus, I hit 22% battery with 88 hours standy and 13 hours usage. That is completely insane.
Back to the Note 5 - look at the graphs on the review here. This phone absolutely DOMINATES the Note 5 across the board, a fact which I can confirm first hand.
I can also tell you that holding the phones side by side looking at the same picture taken on the Note 5, the displays are functionally indistinguishable from the other. (So much for all that resolution, I guess)
This is a large reason why the Note stutters against the 6S Plus. It's pushing a LOT of pixels that aren't really evident in day to day use, especially sitting next to the iPhone.
I guess I finally reached the point, I just want the best phone every year regardless of manufacturer or software.
Until Google makes it's own hardware in house and breaks free of QualComm, Apple is going to beat them every year going forward. I'm not 20 anymore, I don't care about a home screen widget. I want the battery not to drain from some stupid Google Play Services memory drain while the phone is sitting on my desk.
I don't want Samsung Services blowing up the battery either. And - NO - I should not have to root kit, Package Disable, Power Saver, Turn off Location, etc, etc, etc. I paid $1000 for a premium handset with lots of features.
Oddly enough, the iPhone can leave all that crap on and STILL get good battery life. The arguments for Android are shrinking right now. I'll never buy another Samsung phone again. I will miss the S-Pen, but Touchwiz is heinous, even in it's current iteration.
I would really love to see Google put up a fight in the premium handset market, but I don't think their hearts are in the hardware QUITE yet.
Anyways, happy 6S Plus user here, 4+ year droid convert at the moment. We'll see what next year brings.
zeeBomb - Wednesday, November 11, 2015 - link
Ss or bs (sorry I just had to)JTRCK - Friday, November 13, 2015 - link
I actually returned a 6S Plus for the Nexus 6P and the main reason was PRICE. They are as equally performant in day to day tasks, but the Nexus 6P had better multitasking performance for me due to the buttons and added power of a side launcher which is not possible on iPhone. I basically never have to go to the home screen again when using Google docs, searching the web, etc... I tried both out for about a week. The only feature I liked on the iPhone 6S Plus better was the cooler white colors of the LCD; other than that the Nexus 6P was better "for me" in every aspect. The phone "flies" in every sense of the word. No stutters, no lag, no unresponsiveness (typical of Samsungs). I have been an iPhone user since the 3GS. I also used the iPhone 6 Plus this year for 5 months.And I truthfully don't understand all this commotion over the new iPhone 6S Plus being the best phone ever released. Outside of "3D touch," there is not much difference in day to day performance or general use between both this year's model and last year's model. That is generally a great testament to iOS stability and performance. So much so that my old iPhone 4s opened apps faster, surfed faster, multitasked faster, etc, than my now defunct Note 4. Apple has been on top of their game for years, IDK why android fans have only now noticed. But iOS is truly very limited. You will sooner or later find out the gates keep you truly locked in.
But the main factor for me, again, was price. I do not in any way find the iPhone to be a better phone than the Nexus 6P. In fact, I find its system to be inferior in a multitude of ways. Is the iPhone Better than the Note 5 and all its clumsy and useless features? Yes. But the Nexus 6P is in a category all its own. Especially for $650. That is exactly what I paid for the 128GB model compared to the $1,170 I paid for the iPhone 6S Plus.
astroboy888 - Wednesday, November 11, 2015 - link
"FinFET transistors are necessary because as transistors get smaller their leakage (wasted power) goes up, and without FinFETs leakage would spiral out of control. In fact that’s exactly what happened on the 20nm nodes from Samsung and TSMC; both companies thought the leakage of planar transistors could be adequately controlled at 20nm, only for leakage to be a bigger problem than they expected"It is not they "discovered" 20nm leakage was high; therefore they switched to 16nm FinFet. This is an incorrect comment.
FinFet transistors structure had been on the road map and in development at TSMC for more than 10 years. TSMC's first finfet transistor was demonstrated in 2002 when the inventor Professor Chen-Ming Hu of UC Berkeley was working at TSMC as CTO. Therefore Finfet process had always been on the roadmap for 16nm process. The 20nm planar process had always been on the road map as a planar process. Every process node takes about 3-5 years to develop, so the customers (semiconductor chip designers) signs up 3-5 years before hand to co-work with TSMC to design a chip for that process. These were communicated ahead of time and contracts where signed.
In the late 1990s and early 2000s, the semiconductor industry was pushing for SOI (Silicon On Insulator such as GaAs "Gallium Arsenide), which completely eliminates leakage current. But the transistor performance turned out to be too unpredictable and too expensive to manufacture. Therefor the industry stuck with silicon, until FinFet structure was invented in 2000 and manufacturing process perfected some 10 years later.
gonsolo - Thursday, November 12, 2015 - link
If I may suggest something: I'd like to see app startup times as a benchmark from iPhone 5 onwards. This is something I'm doing a lot; waiting for apps to start.