Ever wanted to be able to refocus a photo after the shot has been taken?
That's the premise behind the Lytro, a light-field camera shaped like an elongated cube. Simply take a single image and the Lytro captures all the depth information about a scene. This depth information opens up a whole new way of seeing images as you can play around with the focus point — which is traditionally locked on a single point when taking an image on a conventional camera.
Since the Lytro was released in 2012, manufacturers have been looking for a way to integrate a similar capability into smartphones. Nokia is the first manufacturer to release an app that simulates the effect of the Lytro's refocusing capabilities, available for free download on a range of Lumia handsets. There are other apps that simulate the refocusing effect on iOS.
It's important to note that the Nokia's implementation is purely software based. There is no actual light-field photography at play, just a simulation. So we decided to put the Nokia up against the Lytro in a refocusing battle to determine if you need to shell out the big bucks for a dedicated light-field camera.
If you are unfamiliar with either device, here is a quick rundown of specs:
|Nokia Lumia 1520||Lytro light-field camera|
|f/2.4 lens, no optical zoom||f/2 lens, 8x optical zoom|
|6-inch screen||1.52-inch screen|
|1/2.5-inch sensor size||4.6x4.6mm sensor size|
|32GB internal storage, expandable via microSD||8 or 16GB internal storage|
Rather than thinking about scenes in a flat, two-dimensional way, the idea with light-field photography is to construct your image with depth in mind. This will help ensure that when you click around the finished image, there are plenty of points of interest to focus on.
Our first challenge involves a scene with plenty of depth, from a foreground object right through to a large building in the background. Up first is the Nokia's image:
Here is the Lytro's image:
The first thing you may notice when comparing the two images is the aspect ratio. Thanks to the Lytro's form factor, the image is in a square 1:1 format. The Nokia's image is in 16:9.
As you can see in the first comparison above, once you start clicking around the image from the 1520, the woman in the frame moves. This is because the refocus app actually takes several photos in quick succession at different focus points and combines them together in software — rather than the "true" light-field methodology used in the Lytro. (Note: if you are having trouble seeing the difference on the Nokia's image, click here for the larger version.)
Also, there are only about four or five actual focus points in the Nokia's image, rather than the Lytro, which theoretically offers up any number of focus points thanks to the depth map.
In the comparison above, the Nokia is able to pull out some really defined focus points thanks to the subject in the foreground and background. The Lytro does tend to perform better when there is a more shallow foreground scene, like in the example below.
Click around on the flower to see how the Lytro's image pulls out some more defined information across the focus planes from foreground to background.
Because the Nokia Refocus app only offers the ability to point and shoot — rather than change exposure values like the Lytro does — we have taken all these images on automatic mode for the most accurate comparison purposes.
Filters and editing options
Within the Nokia Refocus app, the editing options include the ability to have all of the image in focus or colour pop. This is where you can tap areas of the image to keep them in colour, converting the rest of the image to black and white.
The colour pop effect on the Nokia gives you the option to pull out a particular colour to highlight in the photo.
However, you can't export still images in colour pop mode; you still need to export a photo that can be refocused as in this example. Click around to see that though the first frame is desaturated, every time you change the focus point the fully coloured image is restored.
The Lytro, meanwhile, has a whole suite of filters to play with. These include colour options like black and white, a mosaic effect and a blur, just to name a few.
A Lytro photo exported with the 8-Track filter applied. Instagram ready!
Also on offer from the light-field camera is an effect called perspective shift. This allows you to change the point of view after taking an image.
Sharing out through the Nokia Refocus app is very simple; just select the Share option from the menu and choose email, messaging or social media. From here, the image will be uploaded to your SkyDrive account and a link created.
Lytro offers free online storage using its pictures.lytro.com subdomain. From the desktop software, you can export and store living pictures to the site for easy sharing. The software (Mac and Windows) also offers the ability to export still images at 1080x1080.
Do I need a Lytro?
Features like manual controls and perspective shift make the Lytro worth the investment if you want to get serious about refocusing images. But if you are happy with some light experimentation, the Nokia Refocus app does a pretty impressive job of simulating a light-field camera in your existing Lumia handset.