This technique involves setting the camera to keep the shutter open while manually zooming out with a medium telephoto lens. Each of these were done with a 10-15 second exposure with a 24-70mm lens. I started by zooming all the way in and then zooming out.
The effect can be quite astonishing.
![Interdimensional Christmas Tree](http://farm4.staticflickr.com/3743/11255232705_0460e39b85_b.jpg)
Focus Zooming