That means that the light field itself is partly a result of the camera's primary lens focal point. Even though the lens can open up to f/2 up to 300mm at its longest zoom, closer focusing still produces a shallower depth of field. The result is that Lytro photos software-focused to objects in the foreground produce shallow depth of field all throughout the image, while those with objects further in the distance produce less depth of field. For this reason, many of the more effectively "refocusable" Lytro images deploy a kind of one-two punch delivered by an object in focus in the very near foreground, which occludes some other object in the background. Clicking on this far object brings it into focus as a kind of visual punch-line.
For example, this image of a Scrabble board is addressed to someone in the foreground. The tiles in the background bokeh are clear enough for the viewer to discern them, and clicking on them shifts focus to reveal a message. The result offers a kind of visual pun or reveal that forms the current Lytro aesthetic, for better or for worse.
Images focused at a medium distance tend to deplete focal distinction due to the increased natural depth of field at further focused distances. This image of a girl playing with a bubble toy illustrates the effect:
The image is set to load at a very close focal distance, that of the bubble gun (A Lytro "living image" can be configured to choose any virtual camera as a starting point of focus). But clicking on the bubbles in the middle of the frame displays microlens data focused on a farther distance from the "natural" point of focus, an image whose native depth of field is simply greater. The resulting action just isn't very interesting. Cinematic techniques like focus in, focus out transitions have set conventions for disclosing a subject over time. But in Lytro's compromise with this filmic technique, the promise of revelation implied by the primary, out of focus portion of the image falls flat. It turns out to be just a mediocre snapshot.
While the effect of natural focal distance can be reduced by zooming the camera's optical zoom and thus bringing far objects nearer together, the idea of a camera whose focal point can be moved arbitrarily doesn't quite correspond with what the Lytro is really capable of.
Many Lytro images turn out this way: looking at a given scene, the photographer assumes that any object the human eye can distinguish can be resolved as a point of focus for the camera. But that's not how the camera sees things. Many living pictures feel like dolled-up versions of ordinary snapshots wrapped in a fancy Flash viewer and a the rhetorical cape of a tech demo.
When the technique works, though, it can deliver a satisfying surprise.
Given the optical circumstances that make most Lytro shots more like two-focus images rather than refocusable images, and considering the square format and small size of the resulting interactive "living" picture, the result is something like a two-frame photographic cartoon, but with both frames set atop one another. At its worst, such a format descends into kitsch, as Abe's Scrabble greeting card above exemplifies. But at its best, this design forces a viewer to consider where to look in an image and why to look there, and thus produces a strange brew of charm and disappointment. If the street photograph seeks the sublime hidden in the everyday, the Lytro living picture seeks the everyday hidden in the everyday, and then reminds you that such obscurity is mundane as well. In an age of irony, the Lytro offers a welcome earnestness. Yet, lest we yearn for sincerity too much, its images step in to remind us that candor is actually kind of tawdry, and maybe we want to stick with irony.
All that said, the Lytro's capabilities aren't fixed, so we must take care not to pass judgement on its aesthetic virtues prematurely. The camera captures the entire light field, and interpolation and display of that data is handled after the fact in software. For this reason, Lytro can update not only its camera firmware but also its desktop and web software to reveal new features of light field postprocessing -- even for images taken before such overhauls.
Recently Lytro rolled out the first such update, adding a perspective shift and what they call "living filters." Perspective shift takes advantage of the fact that the microlens array records images from slightly different perspectives across the focal plane. When reassembled in software, this makes it possible to shift the perspective slightly, which Lytro implements with a click-and-drag interface. Try it with the flowers below:
The result is reminiscent of lenticular printing, a technique sometimes used on collectible cups, Cracker Jack prizes, and theater teaser poster to give a static image the appearance of motion. Unfortunately, like lenticular designs Lytro's perspective shift wears out its novelty quickly. Lenticular images are primarily used as visual piques; an apparently static image seeming to move as a viewer passes by a poster or turns a cup or a card in her hands. They are often used in advertisement or cover images because they help set an image in visual relief against the background noise of a world full of images.
But as a general photographic application, perspective shift feels precious, like multiple-exposure and high dynamic range (HDR) imaging. Lytro's living filters follow suit. they aren't much more than the most rudimentary Photoshop filters applied to the light field data, although the ability to blend different filters at different focal points offers some novelty (try the shot below for an example). The company may have felt a need to compete with Instagram and its ilk in the filterwars, but the addition feels like a mismatch; a serious technological and critical intervention in the history of photography covered in me-too hipster sprinkles.
While the Lytro software isn't currently capable of greater feats, Ng's dissertation discusses at least two other uses of light field photography proven in the research lab. The first is just an implication of the already-released perspective shift feature. Given that the microlens array can see the same scene from different perspectives, light field data can be used to create a 3D stereogram from a single exposure.
The second use, adjustable depth of field, is more complex. Given that the microlens array is capable of capturing all possible planes of focus within the dark chamber light field, computational blending can allow a virtual darkroom program to combine different depths of fields at different points in an image, for example, increasing the depth of field in the background while also retaining a high depth of field in the foreground for an image entirely in focus even if exposed at a large aperture. The computational effort and custom input required to accomplish this feat probably relegates it to a the farther future, perhaps as a kind of Photoshop depth of field "brush" capable of increasing and decreasing focus depth like the dodge and burn tools can do with exposure.
Lytro's ability to update its software has pros and cons for the budding light field photographer. For one part, it's refreshing to find a Silicon Valley company devoted to a truly novel hardware and software solution that suggests actual improvements over time, rather than just another me-too social network app with photo filters. But for another part, Lytro's software puts a lot of control in the hands of Lytro, Inc., and a lot less control in the hands of the photographer. While the software that ships with the camera always allows users to export to a static JPEG image, the Flash-based "living" image is hosted on Lytro's servers and subject to changes in its software and policies. Given today's tolerance for cloud-based services, this quirk may not bother some photographers, but others may squint at the idea that a $400 camera doesn't produce files that can be arbitrarily saved, archived, uploaded, or shared.