Adobe has added a new Focus Blur Selection and Filter to Photoshop 2014 ( Creative Cloud ). This Blur is useful to add a false shallow depth of field affect to photographs, and can be handy when a subject is taken with a messy background.
This tutorial shows how to use both the new Focus Blur selection tool, and the Field Blur filter. ( Note Click on Images to Enlarge them ).
For an example of when this could be useful – let’s take this F11 shot of a Chalkhill Blue. The Butterfly has full focus on both wings – but unfortunately there is distracting grass in the background, that perhaps detracts from the image.
Taking a simlar shot at F5.6 – blurs the background better – however this loses some of the butterflies near wing focus.
What this blur filter allows you to do is artificially blur the background. So having applied the effect described in this tutorial – the following image is produced – with the background blurred, but the subject and flowers remaining as shot by the camera.
The blur filter is applied to anything selected. You can use any method to select this that already exists in Photoshop – but in this tutorial I am using the new Focus Select option.
To use this from the Menu Toolbar – Select -> Focus Area.
Choosing this will bring up the Focus Select Tool – with Photoshops guess as to what is in focus already applied – the rest is blanked out in the selection preview. You can tune the selection by use of the various sliders to produce a good starting point for the fine tuning of the selection. I used the default view mode – which made the out of focus white. You can change the view to other photoshop masking views – using the view mode selection (or keyboard shortcut) at the top to choose one of you preference. Overlay ( V ) is another good choice for seeing the selection and masked out background.
As you can see there are some areas in the above screen capture, that are part of the background. To fine tune the selection using the focus select tool, zoom in on the image to see the selection more clearly. Use the + and – Brush options to paint in / out to the selection. You can change the size of the brush in the normal photoshop way ( [ ] ) – are the windows default keyboard shortcuts for this.
There is also a Refine Edge button, at the bottom for the final fine tuning – however you can not go back to the Focus Select Tool, once this is selected, so ensure you’ve selected what you want before pressing the button.
In my case I refined the selection using the Shift Edge – and I changed the output from New Layer with Mask – to Selection.
The resulting selection was the result of using the Focus Area select tool. (Shown by the black and white dots ( marching ants)).
If there is something that should / should not be in the selection, you can always add/subtract from the selection by using the quick selection tool.
To apply the filter – we must first Inverse the selection – so the background is selected. This is because we want to apply the blur filter to the background, not the main subject.
To do this from the Toolbar Menu – Select -> Inverse
To select the filter from the Toolbar Menu – Filter -> Blur Gallery -> Field Blur
This will bring up the Blur Gallery Filter – with the Field Blur active.
With the filter active – you can then blur the background – so it looks more out of focus.
To do this either move the slider in the toolbar or twist the circle in the middle of the screen. Both methods apply a blur of a set number of pixels.
Once you have the affect you like in the preview – press the OK button, and the filter is applied.