Modify the Depth of Fiels using the Lens Blur Filter (CS only)
Keywords: blur, photography, tutorial, free, photoshop, CS, Lens Blur

1. Open your image.

2. On a new Layer, paint a grayscale reference guide for the filter to work properly. Use white for the "in focus" part of the image, black for the "out of focus" parts and various levels of grays for the intermediate planes.

This might require several Layers, smudging levels of grays and/or gradient for a faded effect.

3. Merge the layers used to create the reference guide (if required).

4. Select the entire Layer (CTRL+A) and Copy it (CTRL+C).

5. Create a new Channel in the Channels Menu.

6. Paste (CTRL+V) the reference guide.

7. Select the RGB Channels (CTRL+~)

8. Go to >Filters>Blur>Lens Blur.

9. Select the Alpha Channel you have created with the grayscale reference guide as a source.

10. Select the required Focal Distance (Strengh of the effect), You can also click directly on the image to select the focus area.

11. Modify the Radius (Intensity).

12. Because this blur effect will remove noise on the image you might want to add some noise back into the image to generate a more realistic effect (More noise will be applied on the "far" selections).

Voilà!