Verdict: 4.5 stars Perspective Efex is a really nice addition to the DxO Nik Collection 3. It offers geometric perspective, distortion and tilt-shift corrections in a simple, user-friendly interface.
Also called 'tilt shift', this effect uses selective blurring to create the optical illusion that you're looking at a tiny model of the world rather than the real thing.
It relies heavily on the choice of image because for this trick to work the subject has to be one that we're used to seeing as a tiny model. For the perspective to be realistic you need a subject you're looking down on from an angle – so street scenes shot from tall buildings are good candidates.
You also need a scene where there aren't too many tall objects, because if it was a real model these would be sharp from the bottom to the top, but this blur effect makes no such distinctions, simply blurring the top and bottom parts of the picture.
This effect works because we've all been conditioned to expect close-ups of small objects to have very shallow depth of field. This can be replicated pretty easily in software and there are a number of different plug-ins and programs that can do it. The real trick, as we've said, is finding the right image to use it on.