This week I’ve been editing the take from a previous trip to Olympic National Park. This image was made on the trail to the Sol Duc Falls in the heart of the park. Walking the trail alone and looking off through the tree trunks immerses you in endless layers of forest life. The photographic problem for this shot was to get foreground and background trees sharp in the frame as this would convey the idea of layers.
With landscapes you typically use a small aperture say f11 to f22 to get a scene in focus front to back. In this scene, with tree trunks scattered throughout the depth of the scene required more than a small aperture. Recall a print advertisement you may have seen of an Apple product like an iPhone. The photo of the product will be at an angle and the entire product will be in focus. They don’t do that with just a small aperture. They use a technique called focus stacking.
Focus stacking worked wonderfully here. The technique requires that you make multiple exposures with your lens focused on progressively different points in the depth of the scene. In this case I focused on the foreground tree then a tree that was farther away and so on. The real magic happens in post processing in Photoshop where you use the File > Scripts > Load Files Into Stack function to place all the exposures into a single file. Then, you use the Edit > Auto Blend Layers function where Photoshop creates masks that reveal only the in-focus areas of each exposure.
Here’s a nice video that explains both the theory and nuts and bolts of Focus Stacking: https://www.youtube.com/watch?v=TAKLyjwbwCo.