Chromatic aberration is a huge image-quality killer – but many photographers don’t know what it is and exactly how it can be prevented.
In this article, I’m going to share all you need to know about chromatic aberration, which includes:
- Exactly why it happens
- How to identify it
- Four simple ways of minimize its effects
So with no further ado, let’s discuss how to deal with that pesky chromatic aberration once and for all.
What is chromatic aberration?
Chromatic aberration (also known as color fringing or even dispersion ) is a common problem in lenses that occurs when colors are incorrectly refracted (bent) by the lens; this particular results in a mismatch on the focal point where the colors do not combine as they should.
Confused? Don’t be. To help understand this a bit better, keep in mind that the focal plane can be your sensor’s point of focus, where all the light from the lens should join collectively to be correctly captured and recorded. But depending on the construction of your lens, your chosen focal length, and even the aperture that you’ve used, certain wavelengths (colors) may reach points in front of or behind the focal plane.
Take a look at the plan below. Do you see how the red, green, and glowing blue light hits the messfühler in different spots? That’s chromatic aberration at work.
When CA happens, you end up with telltale colour fringing around the edges of the photograph. Check out the photo beneath. The left-hand side displays red and green fringes along the sharp edges from the subject. As you can see, it doesn’t look so great.
But although you can edit out lower levels of chromatic aberration in Photoshop and Lightroom , the reality is that it’s annoying to remove LOS ANGELES from each and every photo, in addition every moment you spent coming in contact with up a photo is one minute less that you have for digital photography.
Why does chromatic aberration occur?
Chromatic aberration happens because your lens acts as a prism. It bends light, and much like the triangle-shaped prism produced famous by Pink Floyd, colors passing through the lens are split at different angles.
Here, it’s important to keep in mind that light is actually made up of several different wavelengths (colors). So for the camera’s sensor to detect the combined color of gentle, your lens needs to produce all wavelengths of that particular ray hit the exact same point on your sensor.
It may sound simple, but various wavelengths (and thus various colors) strike your own lens all at once, and each of these wavelengths will behave slightly differently depending on the zoom lens glass that it is passing via.
The task of engineering required to correctly align all of these different light rays is usually achieved by the particular manufacturer’s use of a zoom lens array. In fact , if you would be to pull your lens aside, you’d probably find upward of 16 lens elements – all designed to correct for various things across the light’s journey between your lens and your sensor.
Unfortunately, this is also where chromatic aberration tends to rear its ugly head. Hidden within the design of these lens elements are flaws – either in the cup or the design of the lens itself – which, under specific conditions, may cause your photos to exhibit CA.
Now, I’m not really saying you need a pro-level zoom lens. In fact , a key point is that all lenses suffer from chromatic stupidité in one form or another, no matter the cost. What matters is whether or not your lens exhibits visible chromatic aberration, and whether the amount of visible CALIFORNIA is a dealbreaker for your specific needs.
Furthermore, even if you’re stuck with the CA-prone lens, you can still take steps to prevent image-quality problems, as I discuss in the next area.
How to avoid chromatic aberration defects: 4 methods
Chromatic incongruité is a major problem, especially upon cheap lenses. But the good news is that, if you are trapped working with a lens that exhibits some form of visible chromatic aberration, there are several easy-to-understand ways of remove or minimize the effect on your photos.
1 . Avoid high-contrast scenes
Chromatic aberration tends to surface when shooting high-contrast moments. Particularly problematic are darker subjects surrounded by whitened backdrops, landscapes against the bright sunrise, or – as in the example of the cheetah above – seriously backlit subjects.
There’s no easy in-camera method of avoiding contrast. So there’s often nothing that you can do here except adjust your own
If you absolutely must catch an image as-is, then take in NATURAL and prepare for a touch-up in post-production.
2 . Change your focal length
Although it is nice to have access to a wide range of focal lengths, the fact is that most zoom lens exhibit chromatic aberration at their focal length extremes. So placing the focal length towards the middle of your lens’s range will usually help remove the offending CA.
Note that using a zoom lens at its widest will usually introduce many other defects in your image. When you’re set on a wide-angle perspective, choose a
a few. Stop down your aperture
Although the result will depend on the type of zoom lens you are using, stopping down your aperture helps minimize most lens defects, which includes chromatic aberration.
So rather than using an f/2. 8 or f/4 aperture, try going to f/8 or f/11 – then take a few test shots to see if the chromatic aberration has disappeared.
4. Reframe with your subject at the center of the image
Chromatic aberration is often a lot more noticeable toward the edges of the frame, not the center.
(This is generally due to the curvature of the lens elements. )
Therefore , if you reframe your own shot but put your primary subject closer to the middle , you will often end up with little-to-no chromatic aberration on your subject.
Of course , you may still have noticeable CA around the edges of the frame, but you get the option to crop this particular away. It’s not ideal if you want to retain every pixel inside your photo (e. g., regarding large prints), in which case you should think about one of the other preventative procedures discussed above. But if you are creating small prints or else you plan to distribute your picture online, cropping shouldn’t be considered a big issue.
Chromatic aberration: last words
Well, that’s it:
Everything you need to know about chromatic incongruité, including what it is and how to prevent it.
Now you know how to keep your pictures free of CA. And you can catch stunning photos – even with cheaper lenses.
Over to you:
Are you fighting chromatic aberration in your photos? Have you tried any of the steps discussed above? Share your thoughts (and images) in the responses below.