I feel it prudent to start off by suggesting that when it comes to DOF, it’s going to be better getting it right in camera. However, not getting it quite right, or deciding after the fact, shouldn’t stop you from turning a good or mediocre photo into a better, more pleasing one. I see people adding DOF in post processing all the time, but it’s usually done terribly, hence I can easily spot t. Done well, on the right photo, it can actually be very effective, and you likely have the tool to do it – Photoshop.
We are going to be using the depth map feature, which is going to allow us to add a gradient of defocus areas. Essentially allowing for varying levels of defocus to various parts of the photo giving a much more natural and realistic effect.
Note* – for the duration of this keep black as your foreground color, and white as the background. You can also name the layers anything you like, just keep track of what’s what.
1. Open chosen photo and duplicate it. Then add a new layer. You can hit the button or hit Shift+Cmnd+N on MAC, or Shift+Ctrl+N on PC. Name that layer Defocus Map, and set the opacity to 70%. Select the Gradient Tool (shares a tab with the Paint Bucket in your tool bar). For this I’ll be using the Linear Gradient as found in your Gradient options bar, but there are others depending on what you’re going for and the photo in question.
2. I want me on and the rocks here in the foreground to still be in focus and the background to fall more out of focus. With the gradient tool selected, click from the bottom to the top of the photo to draw a line that is the basis of the gradient. Your photo should look like the one below. The darker areas will be more in focus, and the lighter areas less so. Then change the opacity of that layer to 100% and hide it (click the eye symbol next to layer name).
3. Add another new layer which we’ll call ‘Focal Subject.’ The point of this step is to highlight the primary focus.
4. Select the duplicate background layer. Using the Quick Selection Tool, select the main focus of the photo aka the area to keep most in focus. Once you have an ant line drawn around the subject, go back to the ‘Focal Subject’ layer and select the brush tool. Color over the area within the ant line entirely – don’t worry the ant line will not allow any overspill.
5. While still on the Focal Subject layer, change its opacity to 100%. Then unhide the Defocus Map layer. Next select the Focal Subject layer and ‘Merge Down’ into the Defocus Map layer (right click and hit ‘Merge Down’).
6. Select the entire image in the merged layer by hitting Cmnd/Cntl+A, then Cmnd/Cntl C, to copy the whole thing. Then hide the layer.
7. Switch to the Channels tab next to the Layers tab. Hit the button at the bottom to crate a new channel. Once done, hit Cmnd/Ctrl+V to paste the copied merged layer. A selection called ‘Alpha 1’ should appear. When it does, hide it, and go back to the layers tab.
8. In the Layers tab select your background duplicate layer, and duplicate it again via right click. Title it something like Focal Filter or Lens Blur. then wight that new layer selected go to Filters>Blur>Lens Blur. This is where you alter all the real bokeh parameters. In the Depth Map box drop down menu select ‘Alpha 1,’ and the depth will be applied. Your focal subjects should remain crisp. You can play around with the settings to see what suits best. I upped my radius really high, and chose a triangular shape iris. I also select ‘More Accurate’ from the preview box.
Here is the before and after: