Landscape photographers are obsessed with the idea of sharp images. They use a multitude of methods to ensure that they have a perfectly sharp image right from centimeters from the camera all the way to infinity. One technique they frequently make use of is a technique known as focus stacking. Focus stacking is a very useful tool that is available inside Photoshop. It is particularly useful for creating perfectly focused images which are tack sharp across the entire frame.In other words it is ideal for shooting images where you need a big depth of field.
This technique allows photographers to create landscape images that are crisp. This is something that is difficult to achieve even with expensive lenses. You may try shooting at extremely small apertures like f/22 but your lens will suffer from lens diffraction making it impossible to get images that are perfectly sharp across the frame.
The process of using focus stacking involves creating at least two or more images and then combining (or stacking) them using Photoshop. These images are focused at varying points on the image which when stacked together gives perfect focus at varying points on a single image, something that is impossible to be created using a single exposure.
To make the images you will need to use a tripod. This is to ensure that by and large the images are all lined up and we don’t need to do too much of cropping. In any ways, when we stack them together in Photoshop we can auto-align them to eliminate any compositional errors etc.
Any lens and any camera will do, but the ability to shoot in RAW certainly helps as you can then edit the images to fine tune them or make any local adjustments you may need.
Having shot the images the next step is to import them into Photoshop. As the images are shot in RAW camera RAW should open up automatically. You can make basic white balance adjustments, exposure, contrast etc. and local adjustments such as use a graduated neutral density filter (if required to hold back light from certain parts of the images) and other tweaks. Next, open in the images in Photoshop. Make sure that the changes, if any made, should be applied to all the other images as well.
Next, in Photoshop we will load all the images together using scripts. Click File >Scripts > Load Files Into scripts. This not only opens all the images as separate layers of a single image, but also attempts at aligning them. As I mentioned at the start of this article, you need to select align because invariably when the images were shot there would have been some amount of movement of the camera. Those will be taken care of when you select auto align.
The next step is to blend the images together. This can be done by clicking Edit > Auto Blend Layers. What it does is it creates one final images by blending all the composite layers. It assesses which are the sections of a layer that are sharp and those which are not. It patches the ones that are blurry by using the other layers which may have those specific areas sharper.
Once Photoshop is done doing its bit check the image to see whether the image has come off the way you expected it to be. It invariably does unless the individual images that you used have any issues with them. Once you are satisfied you can no go ahead and flatten the image.