I recently tested an entirely new photography technique for me. Namely ‘ focus-stacking’ technique for macro shooting. Well, it’s no new invention, but I haven’t found time to test it previously. And yet there were some lessons to be learned, I was inspired by the technology immediately. But what is it and when should you use focus stacking?
There are many tools and techniques for creating focus-stacking images, and the latest camera technology now allows you to create a focus stacking images also directly in the camera. I’ll show you a couple of examples of focus stacking in post-processing.
Update: I added another example because Affinity Photo is also able to stack focus-stacking images in its latest version.
The Focus stacking image shows the sharpest points of multiple shots in the same picture
Focus stacking means taking numerous photos of the same object so that focus is shifted slightly between the shots. This method achieves a deeper sharpness area than what would otherwise be possible. In macro shooting, when distances are very short, the sharpness area is often almost non-existent and most of the image remains blurred. Sometimes this is a good thing, and it’s easy to use a large, unsharp part in the picture for a stronger composition.
However, the narrow sharpness area is not always desirable. When you want the subject to be completely sharp, from the closest parts to the most distant ones, then you must use all the means you can find.
Especially if the subject is very close, i.e., the magnification ratio is very high, there can be some problems. The object may no longer fit entirely in the sharpness area, even when using the smallest aperture value of the lens.
In this case, I wanted to get some pictures of willow cats where the willow cat fills almost the entire frame.
Willow Cats Photos were taken with manual focus
In this shoot I used a lens that I screwed onto the camera body. When using the adapter, autofocus was not available, but it didn’t matter because the macro images shooting is done mainly using manual focus.
In Commlite, unlike many other adapters, the electronic connection between the camera and the lens is maintained, which allows you to use the image stabilizer on the glass. Or when using the in-camera-image-stabilization, it automatically works correctly because the focal length of the lens is transmitted to the camera body. This information will also be shown correctly in image’s metadata.
What equipment do you need to create focus-stacking images?
In a camera body using MFT sensor, a 100mm lens will be equivalent to a 200mm focal length in the full frame format. In macro shooting, this is useful because the magnification ratio remains the same, even though the image area being used is smaller, drawing the object even bigger in the finished image. So, yet if the distance remains the same, we can get closer to the subject.
I took 3-7 shots of the willow cats per image, depending on the distance where I took the picture from. The closer you go, the more shots you need to take because the depth of field narrows when the distance to the object gets shorter. The aperture was f/11, and the shutter speed was a few seconds. The tabletop stand is an absolute must-have in macro photography. Otherwise, you must use higher ISO settings, causing dramatically lower image quality.
I could have used a smaller aperture and taken more shots per one image, but this time I used these settings.
A little bit of focus-stacking vocabulary:
Focus Bracketing – refers to taking multiple shots of the same object so that focus is shifted between the shots.
Focus Stacking – Shots are stacked using only the sharpest area of each shot, and combined into one final image.
I found a suitable image editing program online
Finding the right software to stack images was harder than I thought. I was using Affinity Photo image editing program for all the more demanding manipulation, but stacking images was not possible with it at the time. I knew I could have used this feature in Photoshop, but I haven’t owned a Photoshop license anymore for a long time. So I went online again to look for a program to get the stacking done.
I found a program called Helicon Focus. I downloaded a free 30-day trial and made these photos with it. Since this is an expensive program to own, I did not purchase it for myself just yet. Fortunately, nowadays stacking is easy with the lower priced Affinity Photo.
Well, not all the pictures were perfect, but at least I got something out of it even on the first try. I should have taken more shots and on a shorter focus transfer intervals. However, the technical functionality of this focus-stacking technique is apparent here, and the details of the Willow cats were nicely drawn. I think that Canon’s 100mm macro lens is a sharp lens. In fact, these mirrorless crop-sensor camera bodies require optically high-end quality glass.
Affinity Photo is an easy tool for stacking images
I’ll add here another example of the focus stacking image. After shooting the Willow Cats, a new version of the Affinity Photo editing software was released, with the focus merge feature now included for focus stacking.
Last summer, I updated my camera body to a new one featuring automatic focus bracketing feature. That is, the camera takes a desired number of images in a burst, and moves the focus slightly forward between the shots automatically. Just how cool is that!?
So now I got the images a lot easier and more accurately than on the first try. And this time I was able to use autofocus in these shots, since I used the lens. Also, Olympus has created so unimaginable good IBIS (In-Body-Image-Stabilizer), that I didn’t even need a tripod this time! What is not to love here?
I took eight different pictures of the mushroom in a forest near my home. Here are some short instructions how to use the Affinity Photo for creating focus-stacked images.
- First, I used the Capture One to select the focus bracketed shots and exported them into full-size, 16-bit TIFF files, into a separate folder I created for images to be stacked.
- After that, I launched the Affinity Photo, and next, I opened the images into a focus merge project (file-Open-New Focus Merge…).
- The pictures to be merged appeared in the Thumbnail pane. By pressing the OK button, Affinity Photo automatically combined the images for the focus stacked image.
It takes a little moment, the images will blink on the screen when the computer analyzes them and finds the sharpest areas in each shot, but there was nothing else needed to be done by myself. It is possible and often necessary to fine-edit the image after the merge if there appear to be halo rings or anything else that is not desired. However, this time the picture was almost ready after the merge.
Finishing and fine-tuning images is a whole new project, but I left this picture deliberately in the state in which it was after it was merged.
It is even possible to get a sharp focus-stacked image directly in the camera nowadays. I’ve tried it too, and with success. The only drawback is that the image produced by the camera is at least in my camera body only in jpg-format, which slightly limits the image post-processing possibilities.