Review: Nokia 808 PureView: part 2d (Video capture, Rich Recording)

PureView technology advantages and caveats

So far we've seen the way the PureView 41 megapixel sensor gives unrivalled flexibility to stills capture on the Nokia 808 PureView. Ultimate photo quality is usually ahead of the N8's, aided by the 'Pure' oversampling and noise reduction, plus you also get genuinely lossless digital zoom, limited only when the amount of the frame being used gets down to 1:1 pixel usage on the sensor itself.

You won't be surprised to learn that the same technology works in video mode. Shoot in any video mode (i.e. 1080p, 720p or 360p) and you get the benefits of huge amounts of oversampling, sometimes even more so than in still capture mode. Meaning clearer and less digitally noisy videos, especially in low light.

You also get the facility to zoom in losslessly while shooting, effectively using less oversampling and more and more 'raw' pixels the further you zoom. We've seen this lossless digital zoom before, of course, on the Nokia N86 and N8, but the 808 can take it a stage further because of the higher underlying sensor resolution:

1080p video	4x lossless digital zoom
720p video	6x lossless digital zoom
360p video	12x lossless digital zoom

I wouldn't recommend the last mode, partly because noone would choose to shoot in 360p in 2012, and partly because at 12x zoom it's impossible to hold the phone steady enough - you have to carry a tripod around with you, something which rather foils the magic of having a phone-mounted camera. After all, if you carry a tripod around, you might as well have a DSLR too... Having said that, 12x is binocular territory - I even demoed this in the last Phones Show - it's just not a good option to use in the real world.

In contrast, having 4x or 6x zoom to play with when shooting HD video is very freeing. You can shoot exactly what you want to shoot, even if you can't get close enough, framing things with the PureView zoom. Zooming while filming is quite smooth, as you'll see below, and is totally silent, thanks to the lack of moving parts in the 808's 'software camera'.

As with stills though, you do have to bear in mind that with PureView, you get noise-less content or zoom on a reciprocal sliding scale - so zoom right in and there's no oversampling help. A happy compromise is often possible though - some skill will help here in determining the amount of light available and working out how much PureView oversampling help you need. In bright sunshine, you can shoot at full zoom with no real downside.

No downside other than dealing with 'camera shake', of course. As with any degree of zoom on any camcorder (or, here, phone video camera) every slight tremble in your grip will be magnified. In the example video below, only the first train clip was shot on a tripod, all the rest is handheld, to give you an idea of how steady you can/can't be.

Rich Recording

In addition to video capture, the 808 claims to handle exceptional audio too, possibly just as important as what's being shown on-screen. Nokia calls the 808's audio capture "Rich Recording", better even when compared to the output from the digital mikes in the N86 and N8. Impressively, High Amplitude Audio Capture (HAAC) includes improvements to the digital sampling system and means that very loud sounds can be intelligently handled, right up to a claimed 140dB (way louder than a military jet, way louder than a rock concert!), without intrinsic distortion.

Although I couldn't find any rock bands within shooting range this week, see this video embedded below, of Kurt Vile recorded at the Milky Way in Amsterdam on a Nokia 808 PureView yesterday. Very heavy music, very loud and I was STUNNED by the audio quality. Zero distortion, full frequency response:

^{(hat tip to the highly recommended PureView Club)}

Of course, as you'll see below when I tried recording a fast train at 100mph at a distance of around 6 feet, other factors creep in, the way the air itself gets buffeted around in the train's wake. Although 'static' loud noises can be accommodated (in theory), in practice you still get 'wind noise'. In addition, you can hear the way the air itself is being 'torn apart' in the F18 Hornet footage we linked to recently. We're up against the physics of air itself here!

Testing video capture on the 808 PureView

And so to some test video. Some notes:

• the Nokia 808 PureView 1080p footage embedded below isn't full quality, as the phone spits out - the video has gone through iMovie's rendering out to .MOV and then (somewhat more lossy) YouTube's own resampling to a lower bitrate. 
    
• many of the clips were deliberately shot in low light conditions as I was trying to force the PureView oversampling to breaking point. Lots of sunny day clips would have rather defeated the point - not that we've had many sunny days in the UK recently...
    
• all the clips below were in full 'continuous autofocus' mode, the default, which generally works well, though the N8-like 'hyperfocal' system is only ever a tap away, giving crisp results from about a metre to infinity with no auto-focus 'hunting' effects.
    
• to see the clip in 1080p, start it playing in your web browser, click on the gearwheel icon and up the resolution, then maximise to full-screen, assuming your Internet connection can handle the bandwidth.
    
• if you want to see a full MP4 with no resampling/rendering, there are three MP4 downloads below the embedded Flash video.

Detailed comments on each section are included below.

00:00-00:27 Intercity train, no zoom used, overcast/raining, tripod mounted

Listen on headphones if you can, to this and the other clips here - there's a palpable 'you are there' realism to the stereo audio. And even a sense of possible danger as this massive train comes hurtling towards you. As mentioned above, there's significant buffeting in the train's wake - in addition to the noise in the 808's microphone, look closely at the way the phone on a tripod was being shaken!

00:28-00:42 Dusk shot of bus and pedestrian junction, video stabilisation on, zoom used

There's surprisingly little noise, thanks to the quality of the sensor and pixel oversampling - it's not too bad even when zoomed in. The video stabilisation works well too, I think.

00:42-01:00 Guitarist in poor light, zoom used

What's interesting here, apart from the terrific audio quality (again, use headphones) is that you can see the PureView oversampling at work. When zoomed out, the video frame is clean as a whistle, despite the poor lighting on the guitarist. As I start to zoom in, you can see the level of digital noise rising. As maximum zoom (4x), the noise level is as you'd expect for video using any smartphone camera, i.e. this is the video coming off the sensor, with no oversampling. Mind you, this is fully zoomed, any competing phone cameras would be shooting the wider scene with this level of noise(!)

01:00-01:45 Street scene at dusk (note the car tail lights for a reference as to light levels), video stabilisation on, zoom used

I was exploring the zoom again here, note the degree of camera shake at 4x zoom, slightly more than the stabilisation could cope with. This sort of footage really needed a tripod, though I did use the trick of leaning against a wall for stability - most users, with shakier hands, will find 4x zoom even harder to cope with and I'd suggest limiting themselves to 2x zoom, i.e. halfway along the zoom slider's range.

01:45-01:55 An arty shot of rain on the station platform, another Rich Recording test

Again, listen to the natural sound of the persistent rain. Summer, eh? And note the detail in the puddle - starting zoomed, you only really appreciate the power of the PureView zoom once I zoom out again.

01:55-02:14 Getting clever. Zooming in on a fast approaching train, handheld

Very arty, starting zoomed and then zooming out as the train gets closer, then zooming in again as it recedes into the distance. With usable zoom like this built-in though, it should get a few people's creative juices flowing.

02:14-2:53 Cloudy, midday, noisy waterfall

Very picturesque waterfall in full flow, a good test of PureView zoom and Rich Recording, even though some noisy phone reviewer insisted on talking through most of it.... 8-)

 

Raw footage, focus tests and modes

As I said above, all of this video is after iMovie and YouTube resampling. Here are a few 'as is' clips straight from the Nokia 808, for you to download if you want to see some original MP4:

train.mp4 (55MB) - focustest.mp4 (66MB) - focusmodes.mp4 (131MB, screengrabbed above)

The first is the initial clip from the compilation above, looking at PureView quality and the Rich Recording ability to handle very loud noises. 

The second ('focustest') is a look at how fast (or how slow) the continuous auto-focus is to react when the scene subject changes. As you'll see from the clip, the 808 arguably focusses on the wrong leaf at first, then fails to focus on the road scene completely right in the middle of the clip. The focussing algorithms are tuned to work on a timescale of 3 to 5 seconds, similar to those on other camera phones. The problem, of course, is that if the timescale is made too quick, the focus would be 'hunting' again every time something changed in the viewfinder, a leaf blowing in the wind, and so on. So frame contrast is integrated over a number of seconds, which makes sense, though I wasn't altogether happy with the reliability of this feature.

The decent alternative is 'hyperfocal' operation, as on the N8 and demonstrated in the third clip above ('focusmodes'), where the focus distance is algorithmically set to give maximum depth of field for the current light conditions. This has the advantage that almost everything is always crisp enough (watch the way the McDonalds logo gets crisper after I toggle auto-focus off) and with zero 'hunting' effects, but does have the disadavantage that very close up subjects will be blurry. 

Happily, as seen in the video clip, you have the choice of the two focus modes on the 808 and you can change these 'on the fly' in the middle of a clip. Moreover, there's also 'tap to focus', which (as it sounds) immediately maximises contrast for the viewfinder subject on which you tapped. Perfect for ultra-close-ups, though if you then change subject then you do need to remember to tap again, if only to turn auto-focus back on!

Even more happily, the Camera application in the 808 remembers everything about the last mode or settings from one instance to the next. So, if you're happiest in hyperfocal mode, you just turn continuous autofocus off once and then never have to touch the control again - the 808 video camera will remember this preference.

Interface

As with still photography, the 808 presents video capture in three modes:

• 'Automatic' - as it sounds, everything's done for you at 1080p and with the default as 'Continuous auto-focus'. The only on-screen controls are to turn the optional LED video light on and to switch focus modes.
    
• 'Scenes' - the same controls as 'Auto', above, but an extra one to switch 'scenes'. 'Low light'; the default 'Automatic'; 'Sports' (essentially just defaulting to hyperfocal focussing so that there's no hunting while you try and film moving subjects); 'Spotlight' (with subtle white balance adjustments for handling strong stage lighting); and 'Snow' (optimised to take into account the exposure differences needed when filming a snow scene - very handy in Finland, I imagine!)
    
• 'Creative' - with three presets again (as with still photography), you can choose resolution, frame rate (30, 25, 24, 15fps), colour tones (normal, vivid, sepia, black and white), saturation, contrast and sharpness. Plus in the legacy 'Preferences' dialog there's the choice to turn 'Video stabilisation' on.

Though the options here present a huge amount that can be done with video capture, the very essence of filming something interesting usually involves some time sensitivity, i.e. you've got to get filming right now and there's rarely time to stop and think about which settings would be most appropriate. Nokia's default 'Automatic' mode works very well here though and focussing is just about the only thing you ever need to worry about. Besides the fun bit - all that zooming in and out and generally framing your subjects!

The video stabilisation worked well for me but there's not room here to do detailed tests 'with' and 'without' - I'll leave that for an 808 'how to' piece, coming soon here on All About Symbian.

Summary

The combination of PureView oversampling, large high quality optics, lossless zoom flexibility, focus mode choice and Rich Recording audio makes the Nokia 808 PureView the premier video capture phone in the world bar none.

In the world of stills capture, I've shown that the 808 is better than the N8 in most situations and arguably competitive with many standalone cameras - in the video capture world, the gap is wider in each direction. The 808 is an entire level better at video capture than the N8 and other competing smartphones, while being further short of the quality from consumer camcorders at the same price range. Not that the 808 PureView needs to feel embarrassed by this - video capture is perhaps 10% of its functionality and it performs very capably.

In the next review part, I'm going to be turning away from the camera systems at last and looking at the 808's multimedia functions and performance.

Reviewed by Steve Litchfield at 6:17 UTC, July 10th 2012