Design & Operation 

In use, the 808 PureView behaves much like a conventional cameraphone, purely because of its form factor. If you're used to a phone like Apple's iPhone 4S, or any recent high-end Android offering, you won't have any difficulty adjusting to the 808. 

A dedicated focus/shutter button on the right side of the phone (with the screen held in the orientation shown below) acts as a shortcut to activate the camera app even when the phone is sleeping. A 'hard' press is required to open the app and wake the phone - a quick or light press will be ignored, preventing accidental operation of the camera. From sleep to image capture is roughly 2-3 seconds depending on AF acquisition time, which isn't bad at all. Unlike a lot of other smartphones with 'hard' shutter buttons, the 808's shutter release has a two-stage movement, which allows for half-pressing to focus before taking a picture. 

The 808 PureView runs the effectively-defunct Symbian operating system. Future PureView-equipped phones will almost certainly run a version of Microsoft's Windows Phone OS.
The interesting stuff for us is on the back of the phone. The 808's camera module is quite a lump - not surprising considering the size of the sensor. The 808 also features a xenon flash and F2.4 Carl Zeiss lens.
The camera interface is relatively simple but versatile. In the PureView capture modes (8MP/5MP/3MP) you can zoom by simply swiping vertically on the screen.
Nokia makes a spring-loaded clamp with a tripod screw on the base to allow you to use the 808 on a tripod for self-portraits, group shots, or long exposures.

The 808's camera controls are well thought-out and easy to access. A 'hard' button on the upper right side of the phone (when viewed with the LCD facing you) acts as a shutter button in the conventional way - half-press for focus, full press to take a picture. An on-screen shutter release is also available.

 The 808 offers three shooting modes - Automatic, 'Scenes' and Creative. 
For full control over the 808's photographic feature set, you'll need to head into 'Creative' mode. This is where you can select resolution, aspect ratio, and various color/contrast options. 

In 'Creative' mode, you'll see a panel along the left of the screen that provides access to key modes and features including ISO sensitivity, white balance and exposure compensation. Adjusting these settings is a simple matter of scrolling and selecting by touch, but we wish the icons were a little less obscure.

In Use 

With the camera app running, autofocus performance is roughly in line with my expectations from a modern compact camera - a bit of hunting in low-contrast situations, but in normal shooting conditions the 808 focusses in less than a second (usually), and almost always with unerring accuracy. Unexpectedly, the only times I had real issues with focus were when shooting pictures of people, when the face detection would very occasionally just give me a blurry image for no obvious reason.

 This is the default UI in the 808's 'Creative' mode. You can see exposure options ranged on the left, and on the right, a movie/still mode toggle, an on-screen shutter release button, and a shortcut to your library of captured images. When you focus the camera (using a fingre press on the screen, the hardware shutter button or the on-screen shortcut) this on-screen architecture disappears.

The 808's metering system is similarly, very reliable, although the match between live view brightness and final exposure can be pretty wide in especially dark and bright conditions. I've found that it's best to bracket around a little in very bright light to be sure of getting a pleasant exposure. An on-screen histogram would help a lot, but although a histogram appears when you're dialing in exposure compensation, it vanishes again when that screen is dismissed (see below). 

 The 808 offers exposure compensation, and a live histogram is displayed while you're setting the amount of compensation you want, but when you're done, the histogram disappears again. It is not possible to display a 'full time' histogram. 

Shutter lag is effectively non-existent once focus has been acquired. In poor light the 808's built-in AF illuminator kicks in and does a good job of providing enough light for focusing, but in this situation focus slows to usually at least a second for accurate acquisition.  

In full 38MP mode, there's a pause of roughly three seconds after taking a photograph and being able to view it or take another one. In the reduced resolution 3/5/8MP modes this delay is much shorter - roughly one second, for 8MP files. Viewing captured images is quick and easy. Like most modern smartphones, the 808 allows you to flip through captured images by swiping the screen, and double-tapping magnifies the view for critical analysis of detail and focus accuracy.  

I'm wary of making any definitive statements about the 808's battery life since I am using it almost exclusively as a camera, unconnected to a wireless or cell network. That said, in my use of the phone, its battery life has been outstanding, to the extent of being unbelieveably good. I'm used to giving smartphones a precautionary overnight charge before travelling for trips of longer than a day, and I do not, in general, expect much more than 24 hours of life with light to moderate use. The 808 greatly surpassed my expectations, and in fact, during my time with the phone, I was obliged to charge it less frequently than a couple of the compact cameras I was shoot with at the same time.