2D to 3D conversion is when you use a photo editing tool to edit a photo to create an angle that was not captured by the camera. I recently learned how to nicely convert your ordinary 2D photos and turn them into 3D on Photoshop. Here is a link to the tutorial. I did not make this tutorial.
Here is a converted photo of my trip to Boston.
PS: Sorry for resolution. It's actually very very high. Blogger just does this.
PPS: Click on it for slightly higher res.
