The Lytro Light Field camera was probably the most exciting photography product that came out last year. Although it offers low-fi images, it takes photographs in a completely different manner to regular cameras, allowing you to choose and re-choose what element of your photo you want in focus after the fact. Since then, we've heard word that other companies are working on bringing sensors that can also shoot a single image with multiple depths of field. However, Developer Arqball believes it's managed to replicate the Lytro using just your iPhone's sensor and an app: Focus Twist. So how does it do?

Click on different parts of the images to refocus

You'll need a steady hand for good results

For a cheap iPhone app? Not too badly. It's a fairly simple app to use, divided into three sections: the camera, a feed of some of the best Focus Twist images, and a gallery that lets you share image links via Twitter, email, or the Messages app. To take a photo, you need a steady hand. Focus Twist works by taking a number of different shots while focusing on different objects. That takes a few seconds to complete, so if you move your phone during the process you'll end up with imperfect results. You'll notice, especially in the first and last images we've embedded, that objects move slightly when you refocus, which somewhat destroys the illusion that this is a single photograph (see update below). In fact, the output is actually a series of unique JPG files that Arqball's web viewer switches between when you click on different objects.

It won't replace the Lytro, but it's a lot of fun

For good results, you'll need to have an object that's extremely close to the sensor (Arqball recommends your closest object be just 3.5 inches away). That's because of the iPhone 5's small sensor, which won't give you great depth of field for objects further than a couple of feet away. It's extremely limiting and stops Focus Twist being anything more than a sideshow. Priced at $1.99 in Apple's App Store, though, it's quite the sideshow.

Update: We've just had a chat with the team behind the app, who told us that they run an algorithm called "D-Shake" that aligns the individual images of a focus stack. D-Shake fixes a lot of the problems that we noticed with objects moving when you attempt to change focus. As the algorithm is run on the company's servers, which are apparently a little overwhelmed, you won't notice the improvements until a little while after images are uploaded. Arqball hopes to integrate the D-Shake algorithm into its app in the future, but for now says it's working hard on reducing the latency of the image-fixing feature.