Post-processing a handheld macro focus stack

- If you saw last weeks Practicing Photographer, you saw me and a bunch of dead flowers. Well, not dead flowers, but decrepit flowers, and a Canon 5D Mark II with a 100 mm macro lens on it. I was trying handheld focus stacking, and you saw me throw the camera into burst mode, aim at the flowers, and while bursting, move the camera forward a little bit to get a bunch of overlapping images. With the hope that I would be able to now bring them into my computer and stack them together to create an image with the depth of field.

That was last week. So this week, we're gonna do that second part. They're in the computer, and we're gonna see if we can get them stacked together. And I'm gonna take you through that process. It's actually very simple, and here's where we're going to see if this whole handheld thing really works out. You can see that I've got a bunch of stacks here. Now I'm doing this in Lightroom, but you could just as easily do this in Bridge. You could also do it in another application, except that I'm going to use Photoshop for my stacking, so working out of Lightroom and Bridge gives me a really easy workflow. There are applications that are dedicated to the process of focus stacking.

of focus stacking. Helicon Focus is a very good one. But the focus stacking that is built into Photoshop works really well, and if you own Photoshop you've already got it. So, again, either Bridge or Lightroom is going to allow you to easily grab a bunch of images and pass them to that photo stacking mechanism. So I've gone ahead and stacked my images already. When you first pull all of this stuff out of the camera, it's just a ton of data. All of these different pictures, and so you need to be able to sort through, and figure out which ones get stacked. That's actually pretty easy to do because as I move through the images, you can see me just pushing forward here and when I get to the end of the batch, the composition is going to change very suddenly.

the composition is going to change very suddenly. Aha, so this is the beginning of the next batch so I just grabbed everything from here, back to here and stacked them. Took very little time to go through all of these and organize them into stacks, and so now I'm ready to start thinking about combining them all. Before I do that though, let's just do a little reconnaissance here on what we've got. This is the first image in what's going to be my final stack. And in this image, I've got focus very close to me. This edge of the petal is in focus.

As I move forward, I should see that zone of focus moving though the image. Here you can see this is in focus now, while this is not in focus back here. But something to take note of here, that I didn't really notice while I was doing it, it looks like this entire image is blurry and when I come over here and look at my shutter speed, I see that I was at 125th, so I was probably having some handheld shake problems here and I wasn't doing a great job on this first set of pushing in real smoothly.

You can also see how much crop we're probably going to face. Look at the difference between where this petal is in this image, and further down the line it's way, way, way back. This is why I was saying when we were shooting we're gonna need to pad our composition with some extra space, because there is going to be a crop necessary. Now you don't need to go in and analyze your images before you do each stack, I just wanted you to see what a stack of images looks like in their raw format. Speaking of raw format, these are raw images. I'm not going to do any raw conversion. Lightroom's gonna take care of doing that for me.

I've selected all of these, I'm ready to pass them on to Photoshop. Two ways I can do that, I can either right-click to get to this menu, or I can just come up here to the menu bar and go to the photo menu and either place I'm going to see edit in. And from there I'm going to choose open as layers in Photoshop. Now, if this goes well, what's gonna happen is it's gonna automatically create a new document in Photoshop and load each one of these separate images into a separate layer. It's not loading them as raw files, that's not possible, it's having to process them into some kind of actual picture data and it's loading that.

actual picture data and it's loading that. The reason I said if this works, is because I've actually been, there we go Photoshop just came up. I've actually been having some trouble getting the things to move in and load, but it looks like it's doing okay. I think that might be because we're running screen capture software on this computer at the same time here in the background. The screen doesn't always update while it's doing this so what you can't tell is that there is a stack of layers building over here. There's no progress indication to let me know how long this is going to take so, you just have to sit here and wait until it finally stops doing stuff and you see what looks like a finished document with a bunch of layers.

looks like a finished document with a bunch of layers. And here we go. Over here in the layers pallete I've got this big mess of images. All that's going on is each separate image is in it's own layer. The visibility is on in all of them. Obviously I'm only looking at the upper most layer right now. If I turn off the eyeball there, I'm now looking at the one below that, and so on, and so forth. And you can see wow, I was really not steady with my camera. It's wavering all over the place, which means we're probably gonna have a huge crop on this image. I need to get these images aligned, because they are all over the map.

because they are all over the map. So, I'm going to select the first one at the top, scroll down at the bottom and shift select to select all of the layers in this document, and then go to the edit menu and choose auto align layers. I just take the default auto setting and let it rip. And the reason this is necessary is because not only did I do a lousy job of pushing in smoothly, even if I had done it perfectly, there is still a change in composition from image to image, because I'm changing camera position.

Fortunately, Photoshop has an extraordinary align algorithm, it's going to somehow manage to go through here and by shifting each layer left and right, up and down, it's gonna get them all aligned. Like this. If you look here, you can actually see how much it's had to move things. You can see some slight overlap here. Each one of these slightly different rectangles is a separate layer. But look at this, it had to move some way over here, and some way over here. This image is gonna need to be cropped to at least here, and here, and here, and here.

and here. This is why I was saying you need to give it extra space, and we're probably going to see after the stack that it's going to need even more cropping than that 'cause I don't think I did a very good job with the shooting. All of my layers are still stacked here. I'm still up to this point, we've got no increase in depth of field here. I'm still just looking at the top most image. Now's where the exciting part's gonna happen. Now we're gonna actually blend these to combine all the different in focus areas to create an image with deep depth of field. Edit menu, auto blend layers. Make sure your blend method is set to stack images.

You can leave these checked and hit okay. What it's going to do is go through and add a layer mask to each image. And that mask is going to reveal only the part of that image that's in focus. And the layer masks it builds are incredibly sophisticated. It leaves them on the images when it's done, so it's kind of fun sometimes when you're first learning to go in and look at them. In addition to taking forever, I don't think it would actually be possible to do this by hand with any degree of accuracy. It's an incredibly complex operation and it's doing a very good job of it.

So again, what's happening is here by revealing only the visibility of areas that are in focus, we're creating a stack of a bunch of little focused areas that should combine to create an image with much deeper depth of field than we could ever get with any macro lens at any aperture. Wow and here it is, you know I don't usually sit around and actually watch the progress bars while they're happening, but with this operation it's actually kind of fun to do it because the reveal is so startling and so dramatic. Look at this, we've got depth of field all the way from here to here.

from here to here. Now, there's some other stuff going on, let's just go through it. I'm gonna actually call this one a failure, but still it did pretty good. It's selected some areas and that's because I had that auto fill check box checked in that first options box when I did that auto blend. It used content aware fill to automatically fill in this extra space to try to reduce the amount that we need to crop. So I'm going to deselect right now. And it's showing me a final single merged layer on top. I can turn that off and get back to all of my originals and this is what I was saying.

and this is what I was saying. Here I can see all of the fancy layer masks that it's built, and if I want I can even select one and go into the channels palette and view it separately so these are the areas of this layer that it chose. Look, tiny little bits here and there that it's done a very good job of identifying. That's a good way to understand what it is that it's doing if you ever want to go try and correct a problem by repainting the masks by hand. I've tired that before and it's really hard to figure out what's going on. So, why am I calling this image a fail? You probably spotted that already.

You probably spotted that already. These bits in here, I've got decent focus here, and then it goes away, and then it comes back. Those are areas where I didn't have good overlap. Where I was not pushing at the right speed, or maybe the camera wasn't bursting perfectly regularly. Actually, it probably was bursting perfectly regularly I probably wasn't moving perfectly regularly. And so I just missed those areas. That can happen sometimes even if you're working with an actual focus stacking rig.

If you don't calculate your movement interval properly, you won't actually get overlap of depth of field. Now, I can still save this image with a heavy crop, or with some editing. I can use the clone tool. I could flatten this image and use the clone tool to try and retouch some of these. I could do a very dramatic crop and just take out those areas that didn't work very well. Because this is a 5D Mark III, I'm working with a lot of pixels, so I can crop a lot and still have a printable image.

have a printable image. However, I do find that having to crop in this far, my composition just isn't quite as interesting when this is a cropped on 16 layers or whatever it is. I'm not even going to finish that. This is why I said you need to do a lot of takes. That's why you need to do this a bunch. And it was interesting as I was stacking these, I was noticing that I got better at it, as the shooting went on. The first ones, I'm kind of like a drunk focus stacker and then I sober up through the later ones and they get more straight on and much more usable.

So, you saw how long that took I actually went through and stacked all these and pulled out the good ones, the ones that I think worked and I'm very please with the results. Some of these still have some problems. Some focus issues in here. So I think might go in and try to clean those up or crop them out. But some of them were actually completely clean all the way through. Now, this petal is soft focus here, that's fine, it was way in the foreground. If I look, there's a sudden transition there but I don't think it looks weird.

One thing that's strange about macro is we read the scale of things by depth of field. When we see something with very shallow depth of field, we assume it's really small. That's why that toy effect that you can get from a tilt shift lens works because it throws the depth of field into something that's very shallow and we read that as oh we're looking at a little toy, at something very small. So, to maintain a sense of macro, to maintain a sense that we are looking at a flower, you don't necessarily want everything in here perfectly sharp. Throwing this foreground out of focus is a good idea.

It let's us know that we're now into the world of the very small, and that's important. I have found before when I tried to preserve depth of field through the entire scene. It's just not as impressive somehow. You might think well people will just read it as a really giant flower, except we know there's no such thing. These look better when they have some softness still in them. So, I was pleased. Here's another example of where I kept fairly soft depth of field. It was good to have that background shallow and the stem.

And you can see the stem has a few artifacts in it. I think rather than go in and try to paint sharpness into those areas I'll just blur out the rest of it. This is the keeper part of the image anyway. I carry around with me a list of Practicing Photographer topics, I keep it in my phone. By the way on all of these that you're seeing, I have after doing the stack, gone in and done some normal tone and color corrections also this is our last one here. I keep a running list of Practicing Photographer topics on my phone when I think of something, I write it down and I was out one day and I saw a flower and I did this.

and I saw a flower and I did this. And I went oh, this is a good Practicing Photographer, and I wrote it down. I don't know when that was, it was a long time ago. We were looking for stuff to shoot, I was looking through the list and I thought oh, we'll try this handheld macro focus stacking thing, yeah, right. And it works, I honestly am really surprised at how well this works, I wonder why I spent all that money on that rig. This is a very, very good technique to practice. It's one that you can do, even with just a lens reversal ring and turning your lens around backwards because though you will have very, very shallow depth of field, due to lack of aperture control, this just brings it all back.

this just brings it all back. It takes practice, it takes a good amount of light, because you need to keep your shutter speed up, that's one of the advantages of paying money for a rig if you're into this, 'cause you can use longer shutter speeds. But if you get good at it, this is a fantastic macro tool. If you're confused of some of what I'm talking about and you'd like to know more about macro, check out my Macro and Close-Up course.