Tutorials

Use layer masks to make realistic photomontages

by Steve Caplin

Most montages involve combining objects in such a way that they interact with each other. The simplest way of putting one object “inside” another is to use a layer mask in Adobe® Photoshop® CS2, which allows one object to appear to be simultaneously in front of and behind another. Layer masks have more uses than this: they’re one of the most powerful weapons in the photomontage artist’s arsenal, and deserve close inspection to see how you can achieve the best results from them. In this tutorial, we’ll show you how to use a layer mask to place the handheld computer so it’s truly held by the hand.

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1. With the two elements of this simple montage placed together, we can see the problem immediately. This hand may be in the same scene as the Psion, but it isn’t holding it: we need to bring the thumb to the front so that the machine appears to be gripped by it.

In this simple montage, the hand doesn’t appear to be holding the Psion.

2. One solution would be to erase the thumb area from the Psion. But that would be an irrevocable step, and would mean we couldn’t move the machine afterwards without leaving a hole. Instead, choose Layer > Add Layer Mask > Reveal All. The “Reveal All” bit simply means that we begin with nothing hidden. So that we can see what we’re doing, it helps to lower the transparency of the Psion layer first; setting it to 50% lets us see the hand.

Choose “Reveal All” to show the hand behind the Psion.

3. Using a hard-edged brush, simply paint with black over the thumb area. Because the layer is being hidden rather than erased, we can always adjust the mask to show the portions we’ve hidden: simply paint with white to restore the image. At the end, change the opacity back to 100.

Paint over the thumb area with black.

4. The tiny icon immediately to the left of the layer thumbnail will show either a paintbrush or a circle in a gray square, indicating whether you’re working on the layer or its mask. When the Psion is moved, the mask moves with it, as can be seen here: this is because the layer is linked to its mask. To unlink it, click on the tiny chain icon shown between the layer thumbnail and the mask thumbnail and it will disappear.

Unlink the thumb layer from its mask by clicking the tiny chain icon between the layer thumbnail and the mask thumbnail.

5. With the layer unchained from its mask, we can now move it independently and the mask will remain where it is. The object can be shifted, scaled, rotated or distorted however you choose and will still remain grasped by that thumb, because the mask now stays put.

When the layer and its masked are unchained, you can move the layer independently from the mask.

6. Adding shadows helps the effect to look realistic. Two shadows have been added, one for the Psion and one for the hand: each shadow layer uses its target layer as a clipping mask, so it only shows where the two overlap. Keeping the shadows separate makes them easier to adjust later.

Add a shadow to make the effect look realistic.