I’ve written a little bit about a photographic technique I recently learned about called Focus Stacking. My initial subjects were a coin and a stuffed toy alligator. After getting a pretty good feel for the technique, I wanted to try it out ‘in the field’. Over the course of several days I went out every morning and photographed a few subjects, then I came home and figured out how to work with the software.
I found out pretty quickly which subjects were hard to stack. My first subject was a group of small flowers several layers deep in a bush, the program did exactly what I asked it to do, it stacked all of the images… except it wasn’t actually what I wanted, was it? I had made so many items in the frame in-focus that the final stacked image looked flat and disjointed. No, I had to learn when to let things in the frame stay out of focus.
The after image you see below was a labor of love, it was photographed on the fourth day of my adventure into this new world of photographic stacking, as well as, being from set 14 from that photoshoot. But I knew I would like this image when I took it, and I looked forward to getting to set 14. It did not disappoint. This image is a stacking of 10 images.
In my quest to figure out how best to take several images that would be useful, I realized that I needed to take an image as if I wasn’t going to stack them. So at the beginning of each set I would take that photo I would have taken if I was only going to take one, rather than just taking a quick exposure check. So my ‘Before’ is the image I would have taken had I not intended to take several photos to create the After.
Go find out what everyone else did this week for AB Friday Forum here.
I wrote an initial tutorial here which talked about the software I used. For this post I thought I’d show some of the things I’ve learned since that post.
Once I got back to my computer I went through the series of steps I explained here. Even with the align software and the stacking software I would sometimes feel the need to clean up the image in GIMP*. And since I don’t mind painting masks I tend to do more work than is probably necessary. For this image I opened up the final image from the stacking program. Then I opened as layers [File->Open as Layers] all the output files from the align program plus my ‘before’ image.
I ended up cleaning more than is probably necessary, but part of the problem is that there wasn’t enough overlap in my images so there was some banding of blur, much like with the stuffed alligator. With the masks I was able to have the layers gradually blend into each other to lessen the banding. I was also able to force in-focus areas more than the program had decided from the stacking. I was also able to clean up areas where there was some ghosting, as well as force out-of-focus areas to make my subject stand out more.
Lastly, I used the Wavelet Decompose filter, which is a frequency separator, to sharpen my image. I wrote a tutorial about Wavelet Decompose here. I chose wavelet scale 4 and turned the other layers from that filter off.
This entry was posted in ABFriday, flash photography, focus stacking, gimp, macro photography, operation badass, tutorial and tagged ABFriday, nature, nature photography, photography, post processing. Bookmark the permalink.
Woah, so incredibly over my head, Nic! And what the heck is a focus rail that everyone is mentioning?? I do know that focus stacking is useful for macro photography. Is there an application for it in other kinds of photography as well? Amazing after image you created. Isn’t it wonderful how much further down the “stacking learning curve” you are now?? So rewarding when we set out to master a technique and things fall into place. I’m excited for you!
A focusing rail is kind of like a different tripod head, although it can work in conjunction with your current tripod head. It is basically a rail that your camera sits on that you can move your camera forward and backward in micro-adjustments so that you can get the focus just right. Imagine stepping forward or backward handheld with a prime lens, only this is very small movements on the rail.
I would imagine that any subject that could benefit from having several things in focus at once that is difficult to do in one shot would work. Most macro needs so much light that you shoot in such high apertures i.e. f/2.8 that you get lots of things in blur, so focus stacking is very beneficial. I would also say that your subject would have to stay the same (i.e. probably not a person or animal) so that you could take several photos with the focus shifting.
Very interesting discussion of the techniques you used. I know this took a lot of time to put together so it is much appreciated.
A really interesting use of frequency seperation for focus stacking. I have been trialing a software called Helicon, it works well for tripod and focus rail shots, not so great for things shot free hand. I like the overall tones and the focus stacking isolating the flower from the background.
Thanks, Ben! I was considering Zerene Stacker when I found the Open Source software that I used. I used an align program and then a stacking program. I took the image on a tripod, but focused it by hand (rather than a focusing rail) so the alignment shouldn’t be too far off. The programs are command line, which is fine for me, but it is a bit of a learning curve. I may try out one of the GUI programs one day, but currently the programs I’m using are doing a pretty good job.
Thanks, Katie! 😀 I did it by hand, slowly rotating the focus. I have ordered a focusing rail, it should come early next week. All of this was to prepare me for a 5x lens that I just bought, it will definitely need the focusing rail – currently I’m taking pictures of cut flowers and I literally move the vase to find the focus point. But with my 180mm that I used in this post, the focusing rail is not needed. It really depends upon your lens’s area of focus.
Thanks again, Katie! 🙂 I wonder if it would help if you were to bring something to block the wind, like an umbrella perhaps. You would probably have a remote for your camera as well, unless you had a helper to hold the umbrella.
Your after image really pops. Great technique.