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.
Try it here by clicking on the part of the photo you want to be in focus:
There are some tricks to getting the most out of FocusTwist images.
First, you need to frame your photo with a foreground subject that is three to six inches away. The distant subject should fill the background. So a flower in a meadow with a mountain in the distance would be a likely candidate.
When you go to take the picture, tap your screen where you see that close subject so the software knows that is the near focus point. It will figure out the other focus points itself.
Because the camera is going to take a bunch of images, it’s best if the phone is very stationary. That means using a tripod. Joby makes a nice one. If you don’t have a tripod, brace the phone against something steady. The FocusTwist software will do what it can to take the shake out of the images.
If you get an image you like, there are a couple of ways to share it. One is to e-mail it. The email will have a link to the FocusTwist site, where you can see and manipulate the image.
Or the app can post a link to Twitter (the developers are working on the ability to post to Facebook, said Mr. Shelat). But be aware that if you share to Twitter, it’s public.
Your image may also show up on the FocusTwist gallery, which you can see on the app.
