There are a variety of common problems photographers encounter that can take their images down a notch. Chromatic aberration is one of them.
Also known as color fringing or dispersion, chromatic aberration occurs when colors are incorrectly refracted, or bent, by the lens. This causes a mismatch in the colors so they don’t combine as they should.
When this happens, you end up with colors that run throughout the photo and specifically around the edges. While this can be a cool effect, it’s unwanted in most situations.
You can edit out chromatic aberration in Photoshop, but, because it tends to run throughout the photo, it’s a time-consuming and tedious task. Therefore, you want to keep it from happening in the first place.
This article will provide tips on avoiding chromatic aberration so you can get great-looking photos.
What Causes CA?
CA happens because of your lens’s prism effects. It bends light so that the wavelengths, or colors, in the light, split out at different angles. For your camera’s sensor to detect the combined color of the light, the lens needs to make all the wavelengths of a particular ray hit the same point on the sensor.
When various wavelengths hit your lens at once, each will behave differently. Having them align correctly is something achieved by the manufacturer’s lens array. Unfortunately, it’s virtually impossible to get a perfect design.
Many lenses have defects in the glass or the lens design that causes CA to occur, even in high-end lenses. However, it is more likely to happen in a cheaper lens.
How to Avoid CA
One way to avoid CA is to buy an expensive lens. But even a high-end lens can produce CA, and not everyone has the money to spend on top-of-the-line equipment.
Fortunately, there are shooting techniques to integrate that will limit CA from occurring. Here are a few to try out.
Avoid High Contrast Scenes
CA is more likely to happen in high contrast scenes, especially when dark objects are surrounded by white backdrops. To keep this from happening, swap out your backdrop with something that more closely matches your subject’s tones or wait for your lighting conditions to change. If neither of these options is realistic, try shooting in RAW and be prepared to make edits in post-production.
Adjust Your Focal Lengths
Zoom lenses are most likely to produce CA if their focal length is set to extreme settings. Setting the focal length to the middle of the lens range will reduce the likelihood of CA.
Step Down Your Aperture
Stepping down your aperture will minimize most lens defects including CA. If you are stepping down your aperture, you will need to make up for it by reducing your shutter speed or boosting the ISO to compensate for the loss of light.
So if you’re shooting at f/2.8 or f/4 and getting CA, try stepping down to f/8 or f/11 to see if it eliminates your issues.
Reframe Your Shot so Your Subject is in the Center of the Image
CA will be more noticeable at the edge of your shot as opposed to the middle. If you put your subject in the center of the shot, it’s likely you won’t get any CA on the subject. You may get CA at the edges of the photo, but it will be easy to crop it out when you edit.
Chromatic aberration can potentially ruin shots and it’s hard to avoid it. But the tips in this article will help you minimize the risk of it occurring in your photos. What do you do to keep CA at bay?