A Smart Filter is a non-destructive filter, so the settings of the filter can be adjusted when required, turned off or on. Where the filter gets applied can be controlled using the layer mask that is automatically created – so allowing you to experiment freely. To create a Smart Filter, first you need a smart object and when a filter is applied it automatically becomes a Smart Filter.
The following steps will show you how the process works:
Click on a layer in the Layers panel to select the layer.
Right-click on the layer and choose Convert to Smart Object. Alternatively with the layer selected you could go to Layer > Smart Objects > Convert to Smart Object
In the bottom-right corner of the layer thumbnail image you will see an icon informing you that you now have a smart object.
I want to create a depth of field effect where parts of the image that are in the distance look blurred and objects nearer to the camera are in focus. I have selected all the image except the central red tulip using the Quick Selection Tool. I have selected what I want to blur, any part of the image that isn’t selected won’t get blurred.
Go to the Filter menu and choose a filter in the below example I have chose Blur > Gaussian Blur to blur the background. I adjusted the Radius setting to control the blur setting then clicked the OK button.
In the Layers panel you will now see that a Smart Filter has been applied to the layer (see image below). The selection that was created was used to create the black and white layer mask. The selected area is represented as white in the layer mask and this is where the blur effect is applied to.
To adjust the blur setting double-click on the text: Gaussian Blur, to open the Gaussian Blur panel and adjust the radius to change the blur setting.
To hide the Gaussian Blur effect click on the eye icon next to the text: Gaussian Blur. Click back where the eye was to turn the blur effect back on.
To delete the Gaussian Blur effect, right-click on the text: Gaussian Blur and choose: Delete Smart Filter.
Multiple filters can be applied to a smart object as smart filters, so there is lots of opportunity to experiment, be creative and change your mind in a non-destructive way.