When you pre-composed your depth matte you did not move all attributes to the new composition. Make sure you have selected the Move All Elements when you pre-compose.
You might want to give my technique a try. I find it easier and you do not have to pre-compose.
Step by step:
- Create a new comp from your footage
- Add Lens Blur to the footage layer
- Make sure the Footage layer is NOT selected in the timeline
- Select the rectangle tool in the Tool Bar by pressing the Q key
- Make sure that Stroke is set to off and fill is set to gradient
- Edit the gradient if needed so it is linear and black to white
- Double click the Rectangle tool to add a new shape layer
- Press the V key to select the direct selection tool
- Set the blend mode of the shape layer to overlay (you will change this later)
- Select the footage layer
- Set the blur map for Camera Lens Blur to the Shape layer
- Crank up the blur radius to about 50 so you can easily see the result
- Set the Blur Focal Distance to about 128 to put the center of focus at the gray point of the gradient
- Select the Shape Layer and reveal the Gradient Fill then select it to see the start and end points
- Adjust the Start and end points of the gradient to set your focus point, the blend mode makes this easier to see
- Turn off the Shape Layer Visibility to return the footage to a normal look.
- Adjust the Blur radius to achieve the look you want
I find this faster than using Gradient Fill and you have the advantage of being able to create a much more complex gradient to control your focus in a much more realistic way.
thanks a lot!! It does work now..the mistake I made was to put the gradient effect on a pre-compose layer instead of the shape layer