Using the Photomerge Command in Photoshop

The Photomerge command allows you to combine multiple images into one continuous panoramic image. For example, you can take several overlapping photos of a mountain range and put them together into one panoramic shot. If you know you ultimately want to create a Photomerge composition, you can make things easier by making sure that when you shoot your photos, you overlap your individual images by 15 to 40 percent, but no more than 70 percent. Adobe also recommends avoiding using distortion lenses (such as fish-eye) and your camera’s zoom setting. Finally, try to stay in the same position and keep your camera at the same level for each shot. Using a tripod and rotating the head can help you achieve this consistency.

Here are the steps to assemble your own Photomerge composition:
1. Choose File➪Automate➪Photomerge.
You can also choose the Photomerge command from the menu in the File Browser. To do so, select your desired source images and choose Automate Photomerge from the File Browser menu. Using the File Browser method is a timesaver because you can quickly and visually select your images.
2. In the first Photomerge dialog box, choose your source files. You can select from Files (uses individual files you choose), Folder (uses all images in a folder), or Open Files (uses all currently open files) from the Use pop-up menu. Click the Browse button to navigate to your desired files or folder.
If you want to delete a file from the list, select it and click Remove.
3. From the list of files, select the ones you want to merge. Select the Attempt to Automatically Arrange Source files option to direct Photoshop to try to compose the panorama automatically. Click OK.
Photoshop will open and assemble the source files to create the composite panorama.
4. Photoshop alerts you if it cannot automatically composite your source files. You will then have to manually drag the images from the lightbox to the work area in the second Photomerge dialog box to assemble them for yourself.
To manually assemble your composition, drag the image thumbnails from the lightbox area onto the work area with the Select Image tool (the arrow). Or simply double-click on the lightbox thumbnail to add it to the composition. You can also drag an image from the work area and back into the lightbox to remove it from the composition. In addition, you can position the images or rearrange their order also using this same tool. Use the Rotate Image tool to rotate any images. And use the Zoom and Move View (more commonly known as the Hand tool) tools to help view and navigate around your composition. You can also use the Navigator view box to zoom in and out of your composition. Select the Snap to Image option to have Photoshop automatically snap overlapping images into place.
5. To adjust the vanishing point, first select the Perspective option under Settings. Then, click your desired image with the Set Vanishing Point tool, which you can select from the Photomerge tools palette on the left.
Photoshop then changes the perspective of the composition. By default, Photoshop selects the center image as the vanishing point (look for the turquoise border). If you need to, you can move the other images (they will have a red border). Note, however, that when you select the Perspective setting, Photoshop links non-vanishing point images to the vanishing point image. To break the link, click the Normal setting button or separate the images in the work area. You can also drag the vanishing point image back into the lightbox.
6. Adjust the blending of the composition.
Choose Cylindrical Mapping to reduce the bowed distortion you can get when you add perspective to your composition. (Note that you must select Perspective in the Settings area in order to apply cylindrical mapping.) Select Advanced Blending to correct the color differences that can occur from blending images with different exposures. Photoshop then blends the colors and tones. Click Preview to view your settings. Click Exit Preview to return to the Edit mode. You can also view the results in the final, rendered image.
7. Select the Keep as Layers option to save each image in the composite as an individual layer.
8. Click OK to generate the composite panorama as a new Photoshop file which will open in Photoshop. Or click Save Composition to save the composite as a .pmg (Photomerge format) file, which you can later open in the Photomerge dialog box.
To open a previously saved composite (.pmg file), click the Open Composition button in the Photomerge dialog box.