Photoshop Tutorials: Add Realistic Water Drops To A Photo

Step 15: Create A Displacement Map

The basic effect is complete at this point, but we can still make it look a bit more realistic. If this was real water on a real photo, the water would be causing the photo underneath it to look a little distorted, so let's add in that extra bit of realism using a displacement map, which is a scary sounding name for what is really nothing more than a black and white image that we're going to create.

First, select all the water droplets at once by holding down the Ctrl (Win) / Command (Mac) key and clicking on the water drop layer's thumbnail in the Layers palette:

This will place a selection around all of the water drops. Go up to the Select menu at the top of the screen, choose Modify, and then choose Border. When the "Border Selection" dialog box appears, enter a value of about 10 pixels and then click OK:

Then go back up to the Select menu and this time, choose Feather. Enter a Feather Radius value of about 4 pixels and click OK:

When you're done, go back up to the Select menu once again and choose Save Selection. When the "Save Selection" dialog box appears, just click OK to accept the default options and exit out of it. Also, press Ctrl+D (Win) / Command+D (Mac) to deselect your selection around the water drops.

Now switch over to your Channels palette, which is grouped in beside the Layers palette, and you'll see your saved selection at the very bottom in the channel named "Alpha 1". Click on it to select it:

Then click on the small, right-pointing arrow in the top right corner of the Channels palette and select Duplicate Channel from the list of options:

When the "Duplicate Channel" dialog box appears, set the Document option to New, which is going to create a new document out of the channel, and then click OK:

The new document will appear on your screen. This is the document we're going to use for our displacement map. The only thing we have left to do is save it, so go up to the File menu at the top of the screen and select Save As, or use the keyboard shortcut Shift+Ctrl+S (Win) / Shift+Command+S (Mac). Either way brings up the "Save As" dialog box. Name the document whatever you like. I'm going to name mine "water drops", and save the document to your desktop so you can access it easily, since we'll be needing it in a moment.

Once you've saved the new document, you can close out of it. We don't need to have it open anymore.