mirror effect

In a previous Photoshop photo effects tutorial, we learned how to create a simple mirror effect with an image by flipping the right side of the photo horizontally to create a reflection of the left side. In this tutorial, we'll take the same general idea and go much further with it, creating interesting effects, designs and patterns by doing nothing more than flipping, rotating and mirroring the same image over and over again! We'll also experiment with Photoshop's layer blend modes to see how different blend modes can dramatically change our results!
You can use any photo you like for this tutorial, but the effect tends to work best if you start with an image that already contains some sort of interesting pattern or design. I'm going to use this photo of trees. It's the same image I used in the Adding Sunlight Through The Trees tutorial but it should work great thanks to all the tree branches heading off in different directions:

The original image.

Here's just one example of the sort of design or pattern we can create from it in just a few easy steps. Every photo you try this with will give you different results:

One possible design. Your results will depend on your photo and the blend modes you choose.

Important Note: Make sure you work on a copy of your image, not the original, when creating this effect since there won't be any way to get the original back later if you need it. To create a copy, go up to the File menu at the top of the screen and choose Save As, then save the image under a different name.
I'll be using Photoshop CS4 in this tutorial but any version should work. Let's get started!

Step 1: Switch To Full Screen Mode With Menu Bar

Before we begin, let's make a quick change to the way Photoshop is displaying our image so it will be easier to see what we're doing as we make our way through the steps. By default, Photoshop displays images in floating document windows, which is usually fine. In this case though, since we're going to be increasing our canvas size quite a bit, it will be easier for us to work in one of Photoshop's full screen modes. Once you've opened the image you want to work with, go up to the View menu at the top of the screen, choose Screen Mode, and then choose Full Screen Mode With Menu Bar:

Switching to Full Screen Mode With Menu Bar will make it easier to see what we're doing.

You can also cycle through all of Photoshop's screen modes by repeatedly pressing the letter F on your keyboard. Full Screen Mode With Menu Bar will switch Photoshop to full screen, displaying a gray pasteboard area around your photo (the other Full Screen Mode will do the same thing but it hides the Menu Bar, as well as all of your palettes). To get back to the document window mode at any time, go back up to the View menu, choose Screen Mode, and then choose Standard Screen Mode, or simply press the letter F a couple of times.

Step 2: Crop Away Any Unwanted Areas Of The Photo

To begin, let's remove any areas of our image that we don't really need for the effect. In my case, I want to keep the trees themselves but the ground below them doesn't look very interesting and probably won't add anything to the final design or pattern, so I'll crop the ground away. Do do that, I'll select Photoshop's Crop Tool from the Tools panel. I could also press the letter C on my keyboard to select it with the shortcut:

Select the Crop Tool.

With the Crop Tool selected, click and drag a cropping border around the area of the image you want to keep. In my case, I'll click in the top left corner of the photo to add a starting point, then while holding my mouse button down, I'll drag down and to the right to a spot an inch or so above the bottom right corner of the image. This will keep the trees inside the crop border, while everything along the bottom of the image will be cropped away:

Click and drag a cropping border around the area you want to keep.

Press Enter (Win) / Return (Mac) when you're done to crop away the unwanted areas. Here's my image now with the ground along the bottom removed:

The remaining part of the image should create some interesting designs.

Step 3: Duplicate The Background Layer

If we look in our Layers palette, we see that we currently have only one layer, named Background. This is the layer our image is sitting on:

Our Photoshop document contains just one layer at the moment.

We need to create a copy of this layer. To do that, go up to the Layer menu at the top of the screen, choose New, then choose Layer via Copy. Or, for a faster way to duplicate a layer, press the keyboard shortcut Ctrl+J (Win) / Command+J (Mac):

Go to Layer > New > Layer via Copy, or press Ctrl+J (Win) / Command+J (Mac).

Either way tells Photoshop to make a copy of the layer, and if we look again in the Layers palette, we see that sure enough, a new layer, which Photoshop has automatically named "Layer 1", has been added above the original:

The new layer contains its own copy of the photo for us to work with.

Step 4: Double The Width Of The Canvas

Go up to the Image menu at the top of the screen and choose Canvas Size:

Go to Image > Canvas Size.

This opens Photoshop's Canvas Size dialog box which we can use to add more canvas space around our photo. We need to double the current width of our canvas, and we want all of the extra canvas space to appear on the right side of our image. To do that, set the Width value to 200 percent and the Height to 100 percent (which will leave the height of the canvas at its current size). To force the extra canvas space to the right side of the photo, click on the left middle square in the Anchor grid:

Enter 200 percent for the Width, 100 percent for the Height, and click on the left middle square in the Anchor grid.

Click OK when you're done to close out of the dialog box. Photoshop doubles the width of the canvas, adding all of the extra space on the right side of the photo. By default, Photoshop fills the extra canvas space with white:

The extra canvas space appears on the right side of the photo.