Painting with Filters

Here's a sweet technique that allows you to paint with filters or for that matter any other effect you can apply to an image in Photoshop.

First, duplicate the layer by dragging it down to the Make Layer icon at the bottom of the Layers palette or Command-J for the Mac, Control-J for the PC.

Then run the filter, color adjust, whatever... on the duplicate layer.

Add a Layer Mask to the duplicate layer by clicking on the Make Layer Mask icon at the bottom of the Layers palette.

Fill the Layer Mask with black from the Edit, Fill dialog or hit the D key for default colors and then press Command-Delete for the Mac, or Control-Backspace for the PC. The effect on the duplicate layer will disappear because black the Layer Mask hides imagery on the associated layer.

Finally, activate the Paintbrush and paint with white on the Layer Mask. White reveals imagery on the "effect" layer. So now you are "painting" in the effect from the duplicate layer.

For more subtle effects lower the opacity on your paint brush. To remove the effect, paint with black.

(edit)

I wanted to point this one out because I have been asked how to control the effects of sharpening.

Use the technique above to duplicate the image to be sharpened and the run a Filter, Unsharp Mask on it.

Follow the steps to create a Layer Mask, fill with black. The sharpen layer will disappear. Paint white on the Layer Mask for the areas you want sharpened.

Also keep in mind that because the sharpen is on its own layer you can use the Layer Style, Blending Options, Blend if: sliders to hide or show areas based on density and color.