Apple iPhone 4S: Thoroughly Reviewed
by Anand Lal Shimpi & Brian Klug on October 31, 2011 7:45 PM EST- Posted in
- Smartphones
- Apple
- Mobile
- iPhone
- iPhone 4S
Video Capture Quality
The iPhone 4 shot excellent quality 720p30 video and remained arguably the best in that category for a considerable run. Recently though it has been outclassed by smartphones that are shooting 1080p30 with impressive quality which record 720p30 just as well. The 4S catches back up on paper and likewise can capture video at 1080p30. Like every prior iDevice, there are no toggles to change video capture size - it’s always at the device’s maximum quality - 1080p30. Apple also made note of their own gyro-augmented electronic stabilization which the 4S brings. Practically every other smartphone we’ve seen has likewise included some electronic stabilization which leverages the pixels around the target 1080p or 720p area.
We’ve captured videos from the 4S in the dual camera mount alongside the 4, an SGS2, and a reference Canon Vixia HF11 for comparison. I also shot a low light comparison between the 4 and 4S. Showing the differences in video between all of those is something of a challenge, so I’ve done a few different things. First, you can grab the native format 4S versus 4 videos here (442 MB) and the 4S versus SGS2 video here (289 MB).
It’s hard to compare those side by side unless you have multiple instances of VLC open and hit play at the same time, so I also combined and synchronized the comparison videos side by side. The frame is 4096x2048 so we can see actual 1080p frames side by side. Though I realize 4K displays are hard to come by, you at least can see full size images which I’ve synchronized.
It’s readily apparent just how much more dynamic range the 4S has over the 4 when you look at the highlights and dark regions. In addition, the 4S does indeed have better white balance, whereas the 4 changes its white balance a few times as we pan left and right through different levels of brightness and ends up looking blue at the very end of the first clip.
Then comes the SGS2 comparison, and I start out with some unintentional shake where you can really see the 4S’ anti shake kick in. I considered the SGS2’s electronic anti shake pretty good, however its narrower field of view in 1080p capture exacerbates the shaking. Subjectively the two are pretty closely matched in terms of video quality, but the SGS2 runs its continual auto focus a lot and has a few entirely unfocused moments. The 4S’ continual auto focus is much more conservative and often requires a tap to refocus.
The Vixia HF11 comparison gives you an idea how the 4S compares to a consumer level camcorder shooting in its own maximum quality mode. I’d say the 4S actually gives it a run for its money, surprisingly enough, though the 4S (like every smartphone) still has rolling shutter in movement. Finally I shot a low light side by side with the 4S and 4, again white balance is better, but the 4S video in this mode looks a bit noisier than the 4. In addition, the 4S exhibits more lens flaring (something I noticed while shooting stills as well) than the 4.
Subjectively video quality from the 4S is very good, but it falls short in other ways. The 4S shoots video at 1080p30 baseline with 1 reference frame at 24 Mbps, with single channel 64 Kbps AAC audio. If you’ve been following our smartphone reviews, you’ll know that although this is the highest bitrate of any smartphone thus far (Droid 3 we’ve seen at 15 Mbps, SGS2 at 17 Mbps), it’s just baseline and not high profile we’ve seen on Exynos 4210 or OMAP4. In addition, two channel audio is becoming a new norm.
Media Info from video shot on the iPhone 4S
The result is that Apple is compensating for lower encoder efficiency (quality per bit) by encoding their 1080p video at a higher bitrate. Other players are getting the same quality at lower bitrates by using better high profile encoders. We dug a little deeper with some stream analysis software, and it appears that Apple’s A5 SoC is using the same encoder as the A4, complete with the same CAVLC (as opposed to CABAC which the other encoders in OMAP4 or Exynos 4210) and efficiency per frame size. It’s just a bit unfortunate, since the result is that video shot on the 4S will use ~40% more space per minute compared with 1080p30 video shot on other platforms (180 MB for 1 minute on the 4S, 128 MB for 1 minute on the SGS2, and 113 MB for 1 minute on OMAP4).
| iPhone 4S | iPhone 4 |
One last thing to note is that Apple roughly keeps the same cropped field of view size as the 4 on the 4S when shooting video. You can see this behavior in the rollover above. The 4S field of view is just slightly narrower than the 4. Note that the actual area reported from the sensor when in video capture mode is almost always a crop (sometimes with a 2x2 binning) of the full sensor size with some pixels around the frame for image stabilization.
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doobydoo - Friday, December 2, 2011 - link
Hardware wise, the difference between the iPhone 4S CPU/GPU combination and Android competitors, is huge.If you want the best performance, I don't see any other way to turn.
As for the software, I like most users would happily use Android or iOS - they've largely converged anyway.
name99 - Friday, November 4, 2011 - link
"If you had a 4 already your just a "moop" if you upgraded to one of these!"OK, so most US customers on on a 2yr plan. Upgrading for them is impractical, if for no other reason then for carrier reasons. And then you are COMPLAINING that Apple produced an upgrade that (in your eyes) gives them no reason to upgrade???
What exactly is your problem? You're like someone who goes to a restaurant and complains "the food sucks --- and the portions are too small".
dennykins - Tuesday, November 1, 2011 - link
Hey! I have that "Introduction to Modern Optics" book too! Pretty old, but still relevantname99 - Tuesday, November 1, 2011 - link
"It is admittedly curious that Apple hasn’t decided to make some other larger change to distinguish the 4S from the other two"There was, of course, also precious little visual change between iPhone, iPhone3G and iPhone 3GS. Likewise for plenty of other upgrades across the Apple line in the last ten years. I don't know why Anand thinks it's strange. For YEARS Apple has made the point that you buy an iMac --- and you get the what Apple thinks an iMac should be today. You don't buy an iMac XV371. You don't buy an iMac 7. You don't buy an iMac 20011. You buy an iMac --- which may or may not look like its predecessor, which may or may not have last been updated three, six or
nine months ago.
It's obvious that Apple wants to bring that same mindset to phones (and iPads). Screwing with people's expectations of an update in July was simply the first step in breaking the mindset of a particular schedule for upgrades. Of course there are issues that make it more difficult to do this cleanly, for example carrier involvement and the ridiculous subsidized pricing model --- which means that Apple has reason, at least for now, to keep older models around. But there are obvious advantages to Apple in switching to this model, including
- not being forced to release SW too soon. I think we'd all agree iOS5 was released under pressure, and that iOS 5.1 will be the release 5.0 should have been.
- Apple's been able to ignore pressure from a stream of constant Android updates for the past two years, but at some point annual upgrades may just be too slow. At that point it would be nice to have the option of minor upgrades (cf the recent PowerBook Pro upgrades), say boosting the CPU from 800 MHz to 1GHz, without it being a big deal --- something to shut up the crowd that looks at specs, while being ignored by the mass audience that does not care about specs and doesn't want Apple talking about them.
Not that this will stop haters from claiming that "people buy iPhones for fashion"....
KPOM - Tuesday, November 1, 2011 - link
Good observation about the upgrades. Yes, it's entirely possible we'll see minor spec bumps as the iPhone has become a staple of Apple's product line. We don't notice all the the upgrades in the Android world (how many people know or even care about the differences between the Galaxy S, Galaxy S II, and Galaxy S II Skyrocket ?), partly because they happen all the time.Also, Apple has never been a company to change the design simply for the sake of change. They tweak a design until they "get it right," but then stick with it a while. This year's MacBook Air, for instance, is a big update from last year's (Core i5/i7, backlit keyboard, 4GB RAM standard on most models), but they didn't change the external design. It's still selling extremely well and received good reviews. I think it's the same with the iPhone. The 4S has some significant improvements, from the faster processor, better camera, and better antenna.
name99 - Tuesday, November 1, 2011 - link
I'm glad you guys adopted my suggestion to report how snappy a phone feels, based not only on CPU benchmarks but also on the speed of flash, and things like the launch time of apps.In the spirit of constant complaint that is the web, can I now ask that you continue to do this for all future phones, not just iOS devices.
Yes, you have fanboi readers who care only about how wonderful their platform is; but you do also have a number of honest readers who are genuinely interested in things like how the speed of flash (including the speed of SD flash) varies across devices, and how launch times (for comparable apps) vary --- which, of course, depends on both HW and also SW/OS decisions.
Drasca - Tuesday, November 1, 2011 - link
There's a small typo that I'm surprised no one else has caught. Perhaps I am the only one that cares enough about this particular subject enough to. On the last page, 4th to last paragraph, we see:"we’ll hopefully see the technology mature into something more like what years of science fiction moves have promised us."
I believe you mean movies here.
I caught it in particular because I've been discussing amongst my friends how modern technology is the future promise of older science fiction. Oh gosh gee wiz, we have instant mobile communication across the globe, including video! We talk into our portable devices and they think for us. These devices are an extension of ourselves. In a way, we've become like the borg in that we're connected to community at large. Facebook is a form of hive mind group consciousness. Heck, we can track each other near-instantaneously and some folk are vividly aware of each other's locations.
These are interesting times, and what has only previously been explored as supposition has become reality.
I still want my flying cars and teleporters. Also, Holodecks and the AI behind it. Plus, the bridge of the starship enterprise D with its big comfy captain's chair and massive screen.
anishannayya - Wednesday, November 2, 2011 - link
If you want an iPhone, you really don't have a choice. Either you get the 4S or go find an Android phone.shashank7040 - Wednesday, November 2, 2011 - link
Asus Eee Pad being the first tablet With Slide out QWERTY........http://goo.gl/B4rJUthevibenow - Wednesday, November 2, 2011 - link
Check out our review of the Iphone 4shttp://www.youtube.com/watch?v=35v1kkaPM9s