I learned about tilt-shift effect while learning photoshop software. Tilt-shift effect is what adds miniature faking effect to a scene. In miniature faking a scene of life size or object is made to look like a scene of a scale model miniature. Blurred parts of the scene suggests that the depth usually occur in close-ups, which makes the scene seem much smaller than it is, the blur can be done either visually by taking a picture, or after digital processing .


Miniatures can be simulated optically by using lens tilt. Miniature faking using tilt is less effective if a scene includes objects of significant size, such as tall buildings or trees, especially when shoot at a small angle to the ground

Digital Post-processing

A miniature can also be simulated digitally, using sharpness gradients extending from the middle of the scene to the top and bottom, the effect is quite similar to that obtained using lens tilt. Though it has limitations similar to those of lens tilt, more realistic simulation is possible. A simple map depth composed of a linear gradient can be modified to give a sharp uniform objects at the same distance from the camera. Even simple digital techniques allow greater flexibility than optical techniques, including the ability to choose the region of sharpness and the amount of blur to blur areas after the actual was shooting. In addition, miniature digital effects do not require a camera with movements or special (and often very expensive) lens.
Checkout this Miniature faking tutorial for video and these amazing videos created using these techniques (optically as well as digitally).