This extensive video tutorial by Aaron Nace from Phlearn takes a look at how to focus stack several images using Adobe Photoshop and how to shoot for focus stacking.
Focus stacking which is a technique used quite a lot in macro photography (although it can be useful in landscape, architecture, product photography and other situations as well), is actually quite simple. In its core we are taking several images shot with different focus planes and combine them together to create a single image where more of your subject is in focus.
Now you might ask yourself why not use a slower aperture – well – sometimes you simply can’t (this happens a lot in macro photography when you already closed down your aperture to the max) but in many cases you simply don’t want to for all sorts of reasons (one of them is the fact that closing down the aperture can reduce image quality beyond f/11 or so, but there might be other reasons as well).
In this video Nace looks first at how to shoot for focus staking. He suggest using a tripod and a shutter release cable. Next Nace suggest to shoot in manual focus and move the focus slowly “deeper” into the frame. From our experience we can suggest that if you are going to do a lot of focus staking (especially macro or product shots) consider a good macro rail which can really help (as you will be able to move your camera forward instead of changing the focus on your lens.
After you finished shooting go to Photoshop and – go to file>load files into stack. This will open a window where you can choose which files to stack. Nace suggest that you choose align so that if you moved a bit Photoshop will fix that.
Choose all of the layers that were created and go to edit>auto-blend-layers. This will perform the focus stacking of your images. Check stack images and mark v on the seamless tones and colors. That is it!
We have looked into focus stacking several times in the past including a video with Photoshop’s product manager Bryan O’Neil Hughes entitled “How to Do Focus Stacking in Photoshop” and a video by photographer Matthew Saville on “Focus Stacking Landscape images in Photoshop”