Focusing on Focus Stacking Software
Monday 24 December 2012 — Category: Processing
Last month, I wrote a couple of articles about renting a lens for the first time: a high-magnification Yasuhara Nanoha 5x ultra-macro lens. Today’s article — the third in a series of five — will explore the use of two leading focus stacking software applications: Helicon Focus and Zerene Stacker.
As recounted in Wikipedia’s article on focus stacking,
Getting sufficient depth of field can be particularly challenging in macro photography, because depth of field is smaller (shallower) for objects nearer the camera, so if a small object fills the frame, it is often so close that its entire depth cannot be in focus at once. Focus stacking is a digital image processing technique which combines multiple images taken at different focus distances to give a resulting image with a greater depth of field than any of the individual source images. The starting point for focus stacking is a series of images captured at different focal depths; in each image different areas of the sample will be in focus. While none of these images has the sample entirely in focus they collectively contain all the data required to generate an image which has all parts of the sample in focus.
I tried both Helicon Focus and Zerene Stacker with photos taken of a number of different objects during the few days I had the rental lens. For example, the photo to the right is a composite, created by Helicon Focus, of seven different photos of a match head, with each picture taken at a different focus distance. Now, move your mouse over the photo (or tap on the photo on a touch screen), and you will see another composite, created by Zerene Stacker, of the same original seven photos.
These two photos clearly illustrate what I discovered using these two applications. Although the Helicon Focus image does have some sharp areas in the photo, there are also out-of-focus patches. In contrast, Zerene Stacker seems to do a much better job at combining the original photos to produce a final image which is much sharper all around (again, seen by moving your mouse over the photo or tapping on the photo). I found this to be true again and again as I tried photographing various objects. In the end, I abandoned Helicon Focus and used only Zerene Stacker.
Because I’m new to focus stacking software, I didn’t take the time or make the effort to adjust many of the settings both of these programs have to fine tune their operation. I just used the default settings and let 'er rip. It could be very possible that if you knew what you were doing, and could make the proper adjustments, Helicon Focus could turn out to be the better application. But if you just want to get your feet wet and dabble with some elementary focus stacking, I definitely think Zerene Stacker is the way to go. Fortunately, you can find out for yourself, because both applications are available for a free 30-day trial from their respective Web sites. That way you can take them both for a spin and see what you think.
In order to achieve the best results with focus stacking, it would be extremely helpful to have a macro focusing rail. In the next article, I will share about my first experience with this type of equipment.
This article is part three of a five-part series: