Photographers have been wowed by the Lytro, a camera that can refocus a shot after you take it. But the Lytro costs $400 to $500, and that’s a lot to spend for a feature that is a bit of a novelty.
A $2 iPhone app called FocusTwist uses some software processing tricks to imitate what the Lytro does. So you can take some photos with your iPhone using FocusTwist to see if it’s worth it to buy the more sophisticated Lytro.
The way the app works is to take several shots at different focus points – dozens, said the co-creator Ahbi Shelat – and then shift between the images to create the effect.
http://gadgetwise.blogs.nytimes.com/2013/04/25/a-2-app-that-refocus...
