Sometimes we must control the area of effect. For example, imagine to combine these 2 images into one, by using an old man’s head and a young man’s body.
Pay attention on the direction of the light.The light comes from the right in the old man’s image, and comes from the left in the young man’s image.
The image above is just a combination of 2 images. The main problem here is the difference of the light and shadow. It is odd. So I need to add the adjustment layer.
In this case, I used ‘Hue/Saturation’ as the adjustment layer.
By the way, If you want to affect the adjustment layer’s effect only on the layer below, choose ‘Create Clipping Mask’. You can just click the icon below to create ‘Clipping Mask’.
I decreased ‘Saturation’ and ‘Lightness’ both and as the result, I got the image below.
I wanted to put the new effect only on the left side, but the new effect was put on all side. I must restrict the area of the effect.
Choose the layer mask of ‘Hue/Saturation’ and push ‘Ctrl button and ‘I’ button’ at the same time. It means the inverse of the effect. Layer mask becomes Black from White.
After this, Choose ‘White Brush’ and paint only the area which you want to put the effect. You can get like this.
All process can be seen in the GIF below.