With all the advancements lately in the photography world, the ability to perform tasks like focus stacking has been off-shored to built in algorithms in specialized cameras, in post production software (i.e. Photoshop, Lightroom, Aperture, Helicon Focus, and a host of others that have now flooded the market.
Don’t get me wrong, I am all for making things easier, and improving ones workflow, but I do still ascribe to the theory of learning certain fundamentals and essentials for building your photography skills both in composition, and just to understand the mechanics of photography. With that in mind, I’d like to devote a bit of time to discuss the task of focus stacking.
Focus Stacking Versus HDR
First off, focus stacking is used mostly in genres like macro photography, where intricate detail is needed across a range wider than what the aperture will allow for during composition. The principle is much like the layered approach to HDR imagery – where you stack layers of images with different compositions on top of each other and blend the right portions through the entire image.
Where focus stacking differs from HDR is the types of images that you are layering. In HDR images, you are overlaying images with different exposure values over one another. In focus stacking, you are not changing the exposure values, rather just the point of focus. As depth of field drops off both in front of and behind your focusing point, the subject will blur. While this may be an appreciated blurring technique in some cases, in other cases, getting different depths of field from different focusing points can make for a tack sharp macro throughout the range of the subject.
As is most often the case, explaining a photography concept is best done with images, so let’s take a look at an example. For easy demonstration, I took a white cordless phone and placed it on a black background. This way color issues are kept to a minimum…
Notice on the first focusing point, the sharpest point is right near the front? It also quickly drops off into the background as I was shooting at f2.8 The low aperture number means I will have a very shallow depth of field, which is what is causing the blurred background. To bring the rest of it into focus, I need to “stack” more shots that have a different point of focus. So, let’s add another few to the composite:
The end result from stacking all these together can be accomplished by any one of a number of methods ranging from the most time-consuming of doing it manually inside Lightroom or Photoshop, and the most efficient one of using 3rd party software. While several options do exist, the one that has become pretty much the industry standard is that of Helicon Focus! Their quality of processing is, bar none, among the best I’ve seen.
In the meantime, here’s the result of an image that has been focus-stacked:
It’s a quick edit, and done with only having focus-stacked 5 images. If I wanted a really detailed depth of field on something more important than a cordless phone from circa 1990’s, I’d likely have taken at least 10-15 images and massaged them through Helicon Focus more carefully.
For a behind-the-scenes footage video, stop over to the Facebook page! (Be sure to “like” it and share a comment while you are there…)
If you really want to go hip deep into focus stacking and macro photography, there’s a great book by Julian Cremona called Extreme Close Up Photography and Focus Stacking available on Amazon. Good read, and really takes this subject to the Nth degree!