Often, when making images, we come across a situation in which it is difficult to get everything we want in focus. While this can happen in landscape images, if we want both forground and background sharp, it is more often an issue when we start making photographs close up.
The issue lies in the fact that, the closer our subject is to the lens, the less depth of field we have at a given aperature. We can, of course, stop down to increase the depth of field but there are limits to what this can acheive. Further, this approach is counded by the fact that, as the apeture becomes smaller we increase the amount of light that is being bent as it passes of the edges of the aperature increasing softeness. Stopping down also may bring items into focus that we don’t want sharp.
The solution is stacking. We take 2 or more images (I don’t recall every having done 2 but … ) with the focus at different locations in the scene and then use the sharpest parts of each image to get what we want in focus. In the opening image, for example, I used 15 images of very shallow depth of field to get the entire salamander head in focus while allowing the distraction of the background to fall out of focus.
Many years ago, having read an article about this, I tried stacking several images manually. It was tedious, painstaking work. I never tried a second time. Now, we can do this same process through a variety of software. The most common options are Photoshop (which I have used successfully on many occasions including the above image), Helicon Focus and Zerene Stacker.
As I increase my attention to macro, I find myself wondering if I shouldn’t invest in one of the stacking programs. Luckily, both offer free trial periods inwhich to explore their function. So, that is where I am. I have installed both software programs and ran a stacking sequence with each of them. For my subject I selected a set of images that Photoshop has not been able to stack to my satisfaction in hope that this images would challenge each of the other two showing a clear winner. The results are as follows:
This is the output from Photoshop. Looking at the primary subject, one can see large areas out of focus forming halos around the in focus areas.
A zoomed in view of the photoshop stack.
Helicon Focus offers three differant formulas for stacking. They are below.
Helicon method A
Helicon Method B
Helicon Method C
Zerene Stacker also offers different methods of stacking but only two. They are as follows:
Zerene Stacker Dmap method
Zerene Stacker PMax method.
Of the three Helicon Focus outputs, in this case, it appears that method C was slightly better than A or B. Method A appears to have had difficulty with the out of focus background
Zerene Stacker was obvious. Method Dmap created tremendous artifacts in the out of focus background whereas Method PMax did not.
So, by way of comparison, here are zoomed in views of the best methods (in this case) for each software.
Helicon Method C cropped
Zerene Stacker PMax cropped.
It appears to me that there is virtually no difference between the helicon focus stack and the Zerene Stacker stack. Both have provided me with an excellent product. The Zerene stack does appear brighter for some reason though that could easily be addressed post stacking for either option.
Both Software options were fairly easy to navigate however Helicon Focus did appear to be faster at stacking the images.
In the end, I find that either program would be a good investment and I don’t believe one could go wrong either way. I look forward to your thoughts. 🙂