The promise of the Lytro is its ability to refocus a shot after the fact, and it delivers – with some caveats. While you can change focus, it doesn't mean that everything you focus on after taking the picture will be sharp.
While light field technology frees the Lytro from some of the limits of traditional photography, it's still bound to the same old rules. Constraints like shutter speed, aperture and ISO still apply. You won't always get sharp subjects if you're shooting at low shutter speeds and they're moving or if you've moved the camera. Or even sharp images across entire focal planes because something might just be too far or too near.
Not all subjects will produce dramatic results with the focus shifting. If your image is quite flat, with subjects close together, there isn't much change when you shift focus from point to point. Images with some distance between foreground and background work best. Image quality is more Instagram than compact camera. Being 1MP images, there's not much detail in them. High ISO shots can be muddy with some banding visible in some images.
*Note: You need Adobe Flash to see the images below.
The Lytro has two shooting modes, one which will make refocusing easier and one which takes a little more work. The first is Everyday mode, which limits the zoom range to 3.5x. In this mode, the camera will set the re-focus range, or the distance in which subjects can be refocused, automatically. Because the Lytro doesn't need to pre-focus before taking a shot, you can shoot pretty much instantaneously in this mode, and most of your subjects will remain acceptably sharp when you re-focus them later.
Creative mode unlocks the Lytro's full 8x optical zoom, which is an astonishing 35mm equivalent of 43-340mm with a constant f/2 aperture. But the focus range also becomes shallower, and in Creative mode you need to define the focus distance yourself. This means you need to tap to focus and then to take the shot. It's possible to shoot without pre-focusing like you do in Everyday mode, but there's the chance that subjects will turn out blurry if they fall outside of the focus range. When you tap to re-focus on the blurry areas afterwards these subjects remain blurred.
The first image below shows you what we mean. The focus was mistakenly placed on the back wall, way out of the shallow focus range available in Creative mode. So while you can tap to re-focus on the bird cage, it stays blurry. The second image was properly focused on the old man on the left before taking the picture.
While you can already get up pretty close to your subject in Everyday mode, Creative mode unlocks the ability to shoot almost touching your subject. It opens up interesting possibilities for macro photography, and Lytro even says that the camera has no minimum focusing distance – which means you should be able to get as close as you want. In practice though, you have to watch to see that you place your focus correctly, but the Lytro's small low-density screen doesn’t help much when trying to eyeball precise focus on very small or close-up objects.
To view your images, you need to plug your Lytro into a PC and install the Lytro Desktop app. The images are saved to a proprietary format, weighing in at about 16MB each and must be viewed using the Lytro Desktop app. Once the app is installed, you can play around with re-focusing your images. The Lytro Desktop app is another example where Lytro is simplifying the shooting experience, but has perhaps simplified it too much; there's not much you can do within the app to edit your images.
The good news is that you can share these 'living pictures' so that others can also play with the focus. The bad news is that in order to do that, you have to upload them to Lytro's website. You can then share your living pictures with sites like Facebook and embed them on your blog, with Lytro hosting and serving the files, like on this page.
If you prefer to share images the good old way, you can always export your images out to tiny 1080 x 1080 (approx. 1MP) JPEGs. Of course, the re-focusing feature then doesn't work.