Project #3: Simulating Depth of Field

1. The first thing we need to do is create a selection around our two subjects. For this example we will use the Lasso tool and Quick Mask Tool.

   Draw a rough outline of the figure on the left using the Lasso tool. Don't worry about getting it perfect - that will come in the next step.

2. Click on the Quick Mask icon (near the bottom of the Tools palette - 2nd icon) or press the 'Q' key. You should now see a colour masking that's semi-transparent covering the first figure. Next select a medium sized brush.

3. Press the 'Z' key to activate the Zoom tool and zoom in on the left arm. You need to be close enough to correct our Lasso selection. Press 'B' to activate the Paintbrush, and then press 'D' to return the colour palette back to its default settings. Now, simply paint to the edges, don't worry if you make a mistake, by pressing the 'X' key you can change the colour palette around and remove what you don't need. Remember to press 'X' again to get the palette back as it was.

4. Continue this process until the whole figure has been painted over.

5. Once you have done the first figure, press the 'Q' button to return to Standard Editing mode. Then from the Select menu, choose the Save Selection command. Enter a name of your choice in the space provided and click on OK.

6. Repeat the above process for the second figure in the image. Again, save the selection as before but use a different name.

7. Okay, so now we need to have both selection active at the same time. Do this by selecting the Load Selection command from the Select menu. From the drop-down list, choose the name you gave the first selection. Press OK. You will now see the 'marching ants' around the first figure.

8. Go back into the Selection menu and choose Load Selection again. From the drop-down list select the name you gave the second selection.

9. Before you press OK, you need to tell the Selection command that you want to add this selection to the previous one. On the Load Selection dialogue box you will see a heading named 'Operation'. Underneath this heading there are four command options. Click on the second one which is named "Add to Selection". Press OK to accept the settings.

10. You should now have both figures with the 'marching ants' selection around them. Press CTRL+J to copy the figures to a new layer of their own. For now, click on the eye icon next to the new layer to turn it off.

11. Now that we have our main subjects on a layer of their own, it's time to create the Depth of Field. This is done by using Quick Mask and the Gradient tool.

    With the bottom layer active, press 'Q' to enter Quick Mask mode. Next, get the 'Linear Gradient' tool by either pressing 'G' or selecting it from the Tool Box.

12. Press the 'Return' key to access the preferences for the Gradient tool. Set the Gradient setting to Foreground to Background.

13. Position the cursor at the bottom middle of the image. Hold down the Shift key and drag a straight line to bottom of the elbow on the figure.

14. Return back to Standard Editing mode by pressing the 'Q' key. From the Select menu choose the Inverse command (or press CTRL+I).

15. From the Filter menu select Blur and then Gaussian Blur. In the Value box, enter a setting between 3.5 and 5. Press OK to apply the filter. Press CTRL+D to deselect the selection.

    Because we used the Gradient filter in Quick Mask mode, when we apply the Gaussian Blur filter it blurs from top to bottom, getting thinner towards the bottom.

16. Finally, click on the eye icon next to the layer with the two figures on to bring them back into view.

    To tidy up the edges (if necessary), use the Eraser tool set at a small to medium brush.

17. You should now have an image which simulates Depth of Field similar to the ours.