Page 148 - Photoshop for Lightroom Users – Scott Kelby 2nd Edition

Step Seven:
Next, you’re going to do that Blend If trick, again. So, in the Layers panel, double-click on this top layer’s thumbnail (Layer 2) to bring up the Layer Style
dialog again and, in the Blend If section, click-and-drag the top white slider to the left a bit until you see the other two images on the layers below appear
(as seen here). Click OK and that’s all there is to it.

Step Eight:
Optional technique: The Blend If slider worked so well for this because we shot on a white background. But, if you’re going to shoot on another color,
you’re going to need a different technique (it’s an easy one). Instead of using the Blend If sliders, you’re simply going to erase or delete all the extra space
next to your subject in each shot. In this instance, I would get the Rectangular Marquee tool (M) and drag it out over all that blank space to her right (as
seen here), then hit Delete (PC: Backspace) to delete the excess space, and that would reveal the two images on the lower layers (I would, of course, do
the same thing and delete the excess to the left of her on the middle layer, as well). That’s about the quickest way, but you could also just add layer masks
to the two top layers (we looked at working with layer masks like this in the last project), then paint over the blank space with the Brush tool (B), with your
Foreground color set to black, and it would reveal the subject on the lower layers.