How to Create a Focus Stacked Image
Even with incredible advances in camera technology over the years, digital cameras still have limitations. However, post processing software can allow us to overcome these limitations in order to create stunning images limited by nothing except for your creativity.
One thing that most professional landscape photographers are doing is a technique called focus stacking. Often times, a photographer's scene will have a high depth of field, meaning that there may be a foreground element (such as a flower) very close to the lens, and a background element (such as a mountain) very far away from the lens. In this situation, most landscape photographers desire to have the whole scene in focus. If you only took one photo, you'd notice that you'll never have both the mountain and the flower in focus, even with your aperture closed all the way down. Besides, even if you could, f/22 doesn't make for a very sharp image anyways.
To overcome this obstacle, focus stacking was created. Essentially, you take multiple images in the field by moving the focus point around, and then combine them in Photoshop later. In this blog post, I'll be covering how that is done.
In the Field:
Before you can jump on the computer, you have to make sure to take the images correctly in the field. This technique requires you to use a tripod, since you'll need to take the same photo at a different focus point multiple times. If it's windy and you're shooting flowers or grass, it's going to be difficult to combine the images later in Photoshop. If possible, try to keep your focus stacking to scenes that are completely still.
1. Compose your photo, and select the background element as the focus point. You can use manual or autofocus, whichever you are more comfortable with. If you use autofocus, make sure you have it on an autofocus mode where you can move the focus point. You'll want to use an aperture between f/8 and f/13 for optimal results.
2. After you take one photo, without moving your camera, change the focus point to something in the mid ground. Take another photo. Make sure that you don't change any settings other than the focus point,
3. Once you've taken the mid ground shot, you'll want to change the focus point without moving the camera, but this time, to a foreground element. For most photos, three different focus points will do the job. However, if your scene has many more elements that add depth, you may need to take multiple different foreground exposures with different focus points.
1. I recommend loading the photos into Lightroom in order to organize your images. If you like adding profile corrections in order to fix distortion, you can do this now. Make sure that you apply the exact same effect on each photo. Once you're done with that, select all of the photos you'll be using in your focus stack and go to Photo > Edit In > Open as Layers in Photoshop.
2. Once in Photoshop, I recommend renaming the layers by number, with 1 being the closest focus, and the highest number being the furthest away focus (the focus on the background). Select all of the layers and go to Edit > Auto-Align Layers. This will make sure that all of your layers are totally lined up, even if the tripod got slightly bumped while shooting.
3. Now, align the layers so that they are in ascending or descending order, and start from the top. 'Alt/Option + Click' on the layer mask button on the top layer to create a black mask. Now, you'll need to paint white onto the layer mask on the spots where the photo is in focus. One layer at a time, keep painting in the focused part of the images until you reach the bottom layer. Don't put any mask on the bottom layer, as the layers above will cover all of the spots that aren't in focus.
4. Your focus stack is complete! Go about editing the image as you normally would.
Focus stacking is a concept that you'll want to understand if you aim to become a better photographer. Despite not being necessary on all landscape images, you'll find that focusing stacking when you have a great foreground can add a lot of depth to your scene. I hope this guide was helpful, and you'll be able to put this instruction to good use next time you find yourself shooting a scene with a large depth of field!