Convert for Smart Filter

To know what is a Smart Object please visit it's own page.

Smart Filter

Any filter applied to a Smart Object is a Smart Filter.
Smart filters are nondestructive because they are not applied to the image directly they are put in sub layers under the smart object and they can be hidden, edited and deleted without destructing the image it self.

How to apply a smart filter?
You can do that by selecting the layer you want and then go to Filter>> Convert for Smart Filters
After that any filter you apply to that layer will be a smart filter.

How to edit a smart filter?
Double click on the filters layer and the filters dialog box will pop up.
Or right click on the filters layer and select "Edit Smart Filter..."

How to hide smart filters?
Click on the eye icon next to the sub layer of that filter or right click on the filters layer and select "Disable Smart Filter"
To hide all smart filters, click on the eye icon next to the "Smart Filters" layer or right click on the "Smart Filters" layer and select "Disable Smart Filters"

How to delete a smart filter?
Right click on the filters layer and click "Delete Smart Filter"
To delete all smart filters, right click on the "Smart Filters" layer and select "Clear Smart Filters"
 

Smart Filters and Blending Options
A nice feature that you can add to the smart filter is a blending option; Right click on the smart filter layer and select "edit smart filter blending options..."
And choose the blending that you want.

Mask Smart Filters

How to apply a smart filter to a mask?
1- After you apply a smart filter you can see that between your smart filter layer and your smart object layer is a layer called "smart filters" click on that layer
2- Now with a painting tool color where you want the filter to be applied with white, and where you don’t want the filter to be applied black and also you can use the gray color to apply the filter partially
Or
1- Before you apply the smart filter, make a selection within your smart object with any selection tool of where you want the filter to be applied
2- Apply the filter you want, you will notice that you have the same result as the steps above.

How to select the smart filter layer alone?
When you click on the smart filter layer you will see that you can work on it but still you cant see it, because the smart object layer is above it, what you can do to see the smart filter layer alone is to use the alt key and click on the layer.

How to delete the smart filter mask?
Make sure that you have selected the smart filter mask layer then go to the bottom of the layers palette and click on the bin icon
Or you can simply drag the layer to the bin icon and drop it there.

How to disable the smart filter mask?
Simply click on the smart filter mask icon once with your mouse while you have your shift key pressed .