What Chromatic Aberration Is and How to Avoid It

If you're a photographer, you already know how annoying chromatic aberration can be. Why exactly does it happen, and how can you avoid it?

Apart from the focus and composition, there are a few other things that determine the quality of your photos. Things like dust spots, camera shake, the wrong white balance, and other issues can ruin the look of your photos.

Chromatic aberration is one such problem that can add weird color fringes and artifacts to your image. Although your lens is to blame for chromatic aberration, there are ways you can minimize it.

What Is Chromatic Aberration?

Chromatic aberration occurs when your lens doesn't focus all the colors in the color spectrum at the same point. This happens due to dispersion—the phenomenon where white light spreads into different colors due to refraction.

To better illustrate this, let's take the example of a rainbow. When sunlight hits raindrops, it disperses into different colors, appearing as a rainbow. That's exactly what happens in your lens.

Visible light or white light is nothing but a combination of all the colors. The wavelength of each color is different. So when white light passes through an optical element like your lens, it disperses into different colors (with different wavelengths), and your lens focuses each wavelength at various points.

The result? Your images end up blurry with color fringing, where extra streaks of colors show around the edges.

Types of Chromatic Aberration

You should know the two types of chromatic aberration to tackle them effectively.

Longitudinal or Axial Chromatic Aberration occurs when your lens focuses on different colors at different distances. This causes blurriness and color fringing throughout your image. You can correct this by tweaking some settings on your camera.

Lateral or Transverse Chromatic Aberration results from your lens focussing different colors at different points on the same focal plane. This type of aberration is visible only along the edges of the high-contrast scenes. Unfortunately, you have to rely on post-processing to correct this type of aberration.

Many lenses have a combination of both, and often, you have to correct your camera settings and do some edits in post-processing too.

How Can You Minimize Chromatic Aberration?

Chromatic aberration is a normal phenomenon that happens even in expensive lenses. You cannot avoid it altogether, but there are some tricks to reduce it.

Invest in Low-Dispersion Lenses

Camera manufacturers make specialized low-dispersion lenses that can considerably reduce chromatic aberration. For example, Canon uses UD (ultra-low dispersion), and Nikon uses ED (extra-low dispersion) to mark their low-dispersion lenses.

Chromatic dispersion is often more pronounced in cheap lenses. On the other hand, low-dispersion lenses are expensive as they have fluorite elements, which can significantly lessen chromatic aberration.

Use a Deep Depth of Field

We all know how shallow depth of field produces beautiful bokeh. But, a shallow depth field can be your enemy when it comes to chromatic aberration.

Lenses tend to show longitudinal chromatic aberration at their widest aperture. So, close your lens a stop or two to get a cleaner image. For instance, use f/6.3 or f/8 instead of f/2.8. Also, you should adjust your shutter speed and ISO accordingly to let in more light.

Ensure you're not going beyond f/13 as the overall quality of your image decreases after that point. To check your lens' sweet spot, take test shots at different apertures and check at full resolution.

Try a Moderate Focal Length

When you shoot with a zoom lens, chromatic aberration can show up when you fully zoom it. The same goes for completely zooming out too. So when you're focusing, move a few steps forward or backward and leave your lens at a reasonable focal length. This way, you're not pushing your lens to its limits and avoid chromatic aberration.

You can also opt for a good prime lens, which is faster and will give you better image quality.

Tweak Your Composition

Chromatic aberration may not be as visible in a low-contrast scene as in a high-contrast one. Sometimes, all you have to do is just reduce the contrast of your scene.

For example, let's say you're photographing a brightly-colored bird against the sky. If you take the shot as is, you may end up with chromatic aberration around the bird's body. Instead, try an angle where there is some greenery behind your subject, and you will solve the problem.

Most of the chromatic aberration, especially the lateral type, tend to show around the edges of your image. So if you place your subject in the center of the frame, chromatic aberration may not impact your subject at all. You just have to carefully crop the edges later in post-production.

Shoot in RAW

If you're serious about photography, you should already be shooting in RAW. RAW files have unprocessed data straight from your camera's sensor, so you will have all the flexibility while editing. This is especially true for chromatic aberration. Open your image in a RAW processor like Adobe Lightroom, check the Remove Chromatic Aberration box, and you're done.

Sometimes, you may need to edit manually with the Defringe tool option under Lens Corrections to remove chromatic aberration.

Consider Upgrading Your Camera

Many of the latest DSLR cameras come with in-built technology to reduce chromatic aberration in your images. Since there is no sure-fire way to eliminate it, relying on technology to help reduce it is a good idea.

In most cases, you can get rid of the aberration with post-production software, but if you're spending a considerable time on it, researching the latest cameras might be worth it.

Change Your Images to Black and White

Have you tried all our other options and still cannot get rid of the pesky fringes? Sometimes, the solution is not so black and white. Or maybe, it is!

Consider turning your photos black and white as a last resort to salvage them.

The fringes may still be visible as shades of gray at full resolution, but they will not be as evident as in a colored picture. Remember, you must use high-quality editing software to convert your images to black and white to reduce the fringes.

Chromatic Aberration Is a Nuisance, but It Can Be Corrected

It can be annoying when we work so hard to get that perfect image only for it to be ruined by chromatic aberration. Lucky for us, we have the latest gadgets and editing software at our disposal to correct this problem.

Now that you know all about chromatic aberration, you're well-equipped to handle it when it occasionally shows up in your images. But, in the end, invest in quality lenses and cameras if you want your pictures to be top-notch.