Chromatic Aberration, or CA, is an effect caused by the refraction of light into the lens of a camera. Essentially it’s when a lens fails to focus all the colours into a single point, causing an ever so slight colour shift on the edges of some objects, depending on the brightness of said object.
In photography, Chromatic Aberration is a natural effect that occurs depending on the type and quality of lens used. Since it doesn’t necessarily exist naturally in video games, many developers will just use a simulation of the effect instead.
But why is it used in games in the first place? Chromatic aberration is exclusive to camera lenses, which usually don’t exist in video games. The camera you control in-game does not distort or refract light like real cameras; there is no ‘lens’ to refract light in the first place, so why use it?
Adding Chromatic Aberration will make the game seem as if it was filmed with a camera. These days developers or publishers want certain cinematic effects in their games, making the production value seem higher than it actually is (I’m looking at you, letterboxing) and potentially adding more weight to certain scenes.
How demanding is Chromatic Aberration?
Essentially it is just a cinematic effect, much like letter-boxing or vignetting. This means it is purely for personal preference. Whether or not you want to enable it there will be little to no impact on the performance. If we’re really trying to stretch here and I mean really going for a stretch, you might be able to save a single extra frame, if even that.
Is Chromatic Aberration worth enabling?
Chromatic Aberration is mostly down to personal taste. The main question you should ask yourself is: Do I want my game to look like I’m viewing it through the lens of a camera? Obviously it will make your game look more ‘cinematic’, but is that something you really want in your game about killer bunnies shooting rainbows at unicorns? Maybe in your gritty crime detective story, or a photorealistic horror game. Again though, it’s all down to personal preference.
Here’s a couple screenshots that will show you just what Chromatic Aberration does in-game and help you decide whether or not you prefer it enabled or disabled:
As you can see on the text towards the left side, there is an ever so slight blur and colour shift occurring around the edges of the text 'A01'.
Again you can see here the colour shift and subsequent blurriness along the edges of the lamp and wooden board.
Now it is worth noting that both of these games are first-person horror titles utilising photo realistic graphics. In these types of games you'll notice the difference much more significantly, in others you might not notice it as much.
Since Chromatic Aberration does not affect the frame rate it is all down to personal preference. However we recommend to turn it off if you favour stronger image quality in your games as it can add a slight blurriness to the image.