Focus blending in Photoshop CS5
Similar in purpose to the Helicon Focus program, Photoshop CS 5 is capable of taking several images of the same shot, each focused at a different point, and blending them to create a single shot with everything in focus. Theoretically. It usually works pretty well, or at least gives you a good starting point to where you can edit the masks it creates.
First you need the shots. Set an exposure and don’t change it throughout the shooting sequence. It’s probably a good idea to give each exposure some depth of field so that there will be some “in focus” overlap in each shot. But don’t sacrifice movement stopping shutter speed for depth of field.
With your camera firmly locked on your tripod head, take your shots. Start by focusing on the nearest point and change your focus point for each shot, gradually working your way back until you’re focused on the far point. This might take a little experimentation. Shooting at your widest aperture you may need take more shots with finer iterations than if you can use an aperture that gives you more depth of field. Number of shots is up to you, but it’s easier to not include shots you already have if you don’t need them than to not have shots you really needed.
Once you’ve taken the photographs and have downloaded them to the computer you have several options on how you get them into Photoshop:
- Import pictures into Lightroom
- Select all the shots you want to blend for focus
- In the Library Module, either right-click (Ctrl-click on Mac) on one of the chosen images or click on Photo in the Menu Bar.
- Choose Edit In, and then Open as Layers in Photoshop
- Navigate to where the images are stored on the hard drive
- Select the images.
- In the menu bar, go to Tools>Photoshop>Load Files into Photoshop Layers
You can also open all the images directly from Photoshop if you choose by using the File>Open menu and navigating to where you’ve stored the images. Once they are all opened in Photoshop, use the Move Tool to place them all in one document. This will create several layers. Hold down the Shift Key when moving so that the pixels are aligned.
Once you’re in Photoshop and you have one document with a layer for each image, do the following:
- In the Layers Palette, select all the layers by using the standard Ctrl-Click and Shift-Click methods.
- Go to Edit>Auto Align Layers and choose the Auto method
After alignment is complete then
- Go to Edit>Auto Blend Layers and choose Stack Images
- Crop final image as needed
If you started the process from Lightroom, Save the image and it will be added to your catalog. You can then go back into Lightroom and make your usual adjustments.
That’s it. If you use full sized 16-bit images this could take some time, depending on your processor’s power and the amount of RAM in your computer. To speed things up, consider converting the layered Photoshop document to 8-bit and reducing the size before you begin the Layer Alignment process. This is a good idea if you just want to see if this process will work for your picture before you commit the computer to the time of actually processing the full size image.