We will tell you a secret: those crystal clear images are made with a magic wand called focus stacking.
What Is Focus Stacking?
Have you heard of HDR images? High Dynamic Range images are made by taking three separate photos at three different exposures and merging them together in editing software. This technique brings out the details and vivid colors.
Focus stacking is something along similar lines. It involves taking multiple images at different focus distances and stacking them in editing software to get one crisp-looking picture.
Why You Should Focus Stack Your Images
The usual technique to get the corner to corner sharpness in an image is to close down the aperture (higher f-number). Have you ever taken a picture at f/22? If yes, you should know that it will be nowhere near the glistening photos online. The problem with a higher f-number is that your lens will suffer diffraction at small apertures.
If you remember anything from your physics lessons, you may know that light travels in a straight line. When your aperture is fully open, there is enough space for light to travel. On the other hand, when your aperture is small, light rays diffract and interfere with each other. As a result, your images will be blurry, especially around the edges.
Most lenses suffer diffraction at an f-number greater than f/13. However, cheaper lenses tend to show diffraction at lower f-numbers. Also, diffraction is more visible in cropped sensor cameras than in full-frame cameras.
To check your camera and lens’ sweet spot, you can try taking pictures at different apertures and reviewing the photo’s quality at a hundred percent zoom.
Take Spectacular Landscape Images
In landscape photography, you want the distant mountains in focus as much as your closer subjects. So if you dial your aperture to say, f/22, you may get the mountains in focus, but your photo will overall lack quality.
The best way to fix the issue is to take multiple pictures at a reasonable f-number like f/8, focusing on different places in your scene. You can then focus stack the images in your editing software.
Nail Your Macro Photos
Macro lenses are great for getting up close to your subject and showcasing them in life-size, but they have a downside: the depth of field is very shallow in macro lenses.
The close focusing distance and the magnification factor make the depth of field tiny—usually mere millimeters. So, it is impossible to get your subject entirely in focus with macro lenses, even with an increased f-number. The solution? Focus stacking.
Let Your Product Photos Shine
In product photos, especially photos of jewelry and watches, it is not easy to capture all the tiny details with traditional photography and editing techniques. Focus stacking is the answer to bringing out the details and making your products look crisp for e-commerce use.
How to Focus Stack
The name focus stacking may sound like something complicated, but it is a relatively simple technique. To focus stack your images, you need a photo editing software like Adobe Photoshop.
There is no set number of images you can focus stack—you need at least two photos, and you can add as many as it takes to get all parts of your subject in focus. You will make that decision depending on your subject.
Macro and product photographers often take over 20 images to ensure every bit of the image is in focus. On the other hand, landscape photographers tend to go for only a couple of photos because their subjects are usually more prominent, and wide-angle lenses tend to be sharp with a good depth of field.
Hardware Requirements
Unless you’re a macro photographer, you don’t need any other special hardware for focus stacking. However, it will help if you have a tripod to capture the photos because it is crucial not to change your composition too much.
As with composition, aim to keep your exposure consistent. You can use continuous lighting to maintain the same exposure in all of your photos. If there is a big difference between your shots, your final image may not look right.
When working with macro, the depth of field is usually in millimeters. So, it may not be possible to get all of your subject in focus by randomly choosing focus distances. You may need special equipment like focus rails and bellows to select them precisely.
A focus rail has a mechanism that lets you move your camera in millimeter increments. It attaches to your tripod, and you can adjust your camera’s movement in both front and back and side to side directions. An extension bellows does the same thing, but it can also increase your subject’s magnification.
Advanced macro photographers use automated rails to take images at different focus distances. One of the best in the market is Helicon Focus, which includes hardware to control your camera along with focus stacking software.
You Don’t Always Need to Focus Stack
As with every editing technique, it’s better not to go overboard with focus stacking. For example, it is not a good idea to focus stack portrait images. Stacking too many images can also significantly slow your computer down.
Although focus stacking is fun, don’t be too obsessed about it—feel free to take the photos at larger f-numbers if you’re okay with a little bit of blurriness. Also, everyone loves a good-looking bokeh. So, if that is what you want in your photos, go for it. Call it artistic freedom—there is no rule saying that your images must be sharp from corner to corner.
Ace Your Photography Game With Focus Stacking
Focus stacking is an effective technique that will make your photos look professional. Apart from that, focus stacking will also urge you to pay attention to your composition and exposure.
Remember, learning various editing techniques will give you the confidence to handle unexpected situations. So, if you have never tried focus stacking before, now is the time.
