Do you often find yourself struggling to get images that look perfectly sharp from your toes all the way to infinity? Sometimes the hyper focal distance technique will do the job, but on other days, it simply won’t save you. Are you planning to print large images? Focus Stacking might be for you!
Don’t get me wrong, it can be really interesting to have a completely out of focus foreground as it adds a lot of depth to the scene but if you have let’s say a rock in the lower right corner that is slightly out of focus, it’s not going to look good…it’s going to look as if you made a mistake while shooting.
Focus Stacking can be done both manually or using a software…in this article, I will guide you through all the steps you’ll need to follow in order to get perfectly focus stacked and really sharp images. Follow these steps from the moment of capture all the way to your very last mouse click behind your computer screen and you will get great results guaranteed!!
First of all, I highly recommend you to shoot with a specific White Balance setting in order to make sure the white balance won’t shift from one image to the next. I know it can always be fixed in post processing after but why would you do an extra step if it can be avoided? I personally shoot with a DSLR still…yeah I know, call me dinosaur as I haven’t done the switch to a mirrorless camera yet! I always shoot in Live View which means with the mirror up. This allows me to magnify what I see on the back lcd screen in order to focus on the closest element of my composition and shoot one image. After the first image is done, I will magnify once more on the screen and focus on an element located a little further and shoot again…and so on until I get images of the furthest elements of my composition. Depending on how close I am from my foreground, I can shoot up to ten different images focused at different focus distances. Some will say I don’t need that many images and I’ll have to admit that they are probably right...but since we are in the digital age which means an extra frame or two won’t hurt anybody and worse case scenario, you can always delete those unused frames when you get home. On the other hand, if you don’t shoot enough and end up missing a frame or two, the Focus Stacking simply won’t be successful and you will have a few elements that aren’t perfectly sharp in your shot.
Ok so you are done photographing, you backup up your images on your hard drive and are back home? It’s now time to go through all those previously captured images and edit them! Let me guide you through my Focus Stacking workflow;
RAW FILES ADJUSTMENTS
-1st; You will need to do your initial RAW adjustments exactly as you would in any other situation. And when you are done working on your RAW files, choose all the ones required for that specific focus stacking then Right Click on your mouse and choose Open as Layers in Photoshop. (Modify in / Open as Layers in Photoshop) It may take a few minutes for them to open depending on what kind of processing power your computer has.
ARRANGE YOUR LAYERS
-2nd; The layer order is very important here. You background layer should always be the image that was focused to the furthest element first. I will explain why later…
-3rd; Make sure to lock your background layer if it isn’t already locked. (Layer / Lock Layer and choose the option All)
USE GUIDE LINES
-4th; You will now need to drag four guide lines, one for each side of your canvas. Now how do I add those guide lines you may ask? There is one ruler at the top and one at the left side of your screen. All you have to do is click and drag the guide line until positioned at the right place. If for any reason you do not see the rulers, press cmd R (or ctrl R on a PC) and the rulers should appear. One other fun tricks to facilitate the positioning of the guide lines would be to use the SNAP tool which will act as a magnet when ever the guide lines are reaching the edges of the frame. To activate the SNAP tool, go to top menu and choose (MENU / SNAP TO / ALL) and the guide lines should now easily snap to the edges of your image.
AUTO ALIGN LAYERS
-5th; The next step is to select all layers and auto align them all together. (Edit / Auto Align Layers). Photoshop should be intelligent enough to see that you desire to do a Focus Stacking so go with the default settings. You won’t need to check any boxes here and you can go with Automatic Mode.
WHY IS MY IMAGE BIGGER NOW?
-6th; Now that all layers are aligned together, you probably noticed that your canvas now exceeds the guide lines you previously dragged around your image...how come? In order for all the layers to align together properly, Photoshop manipulated and transformed all layers except for the one that was initially locked in order to align them together. This is due to the fact that when ever you change focus distance on your lens, it will make as if you also changed focal length. That phenomena is absolutely normal and is called lens breathing. When ever focusing at a different distance, an optical element of your lens will actually move affecting the diopter of the lens at the same time. And for that reason, Photoshop will need to transform all layers to align them all together.
CROP YOUR CANVAS
-7th; You will now need to manually crop the image back to its original resolution which basically is where you previously dragged some guide lines. Here’s why, the part of the images now exceeding the guide lines won't be in focus. As mentioned at the very beginning of the process, since our background image is the one focused on the furthest element of the image, everything exceeding the guide lines will need to be cropped out since those pixels are most likely going to be out of focus. You will need to get rid of those out of focus pixels by cropping everything exceeding the guide lines in order to get the best possible results from focus stacking. And since we recently activated the snap tool, the crop tool should also be much easier to use as it will also snap to the guide lines.
-8th; Select all layers and group them together. You should name this group Focus. (Cmd G or Ctrl G on a PC) I always make sure to name my layers and groups according to what they actually are...it makes things a lot easier in the future when ever you are looking for a specific layer.
CREATE A BACKUP FOLDER
-9th; Right click on the group and choose Duplicate Group, name it Back Up and we'll use it later. You should also put a black mask on every layers from this Back Up group. Unlocking the Back Up copy of the background can be done by simply clicking on the LOCK. If you are wondering why you just copied the FOCUS group, the reason is simple. Photoshop is good at everything but not great at Focus Stacking. Photoshop will make stacking errors in most cases and by creating a copy of the Back Up group, this will allow you to correct those errors by simply masking in or out details from the needed layer.
AUTO BLEND LAYERS
-10th; Next step will be to auto blend all layers. (Edit / Auto Blend Images) Once again, Photoshop should instantly understand your intention. You should already have a check in the Stack Images box as soon as you open the window….if not, just choose Stack Images. You will also have two unchecked boxes at the bottom of this window. You should check the first one as Photoshop will adjust Colors and Tones automatically ifor smooth transitioning between every image while stacking. The second box should remain unchecked. I didn’t get good results on most occasions when I checked this one. Press OK and let your device do the Focus Stacking job for you.
LOOK FOR BLENDING ERRORS
-11th; The last step will be to pixel peep in order to find blending errors…I recommend you navigate on your images at least 200% magnification and look again and again and again everywhere for blurry spots like the one in the supplied screen shot below. Photoshop may also have duplicated some elements. If you had some moving elements when you were photographing the scene like humans, Photoshop might have duplicated them… If you find any stacking errors, you’ll just need to recover the details from the right layer in your Back Up layer group!
And that’s it!! You should now have a perfectly Focus Stacked and sharp image from corner to corner! It is a bit time consuming but the end result will blow your mind away! You will need to practice in order to learn all those steps but I am sure you will quickly become a master at the Art of Focus Stacking! ;-)