Chromatic aberration is a phenomenon which happens when lens (or lenses) fail to focus the whole light spectrum into a single spot (or at least close to it). Instead of natural looking image, you will end up with colour distortion, especially on the edges of viewable area and on objects which contrast well with the background or other objects. CA is also known as colour fringing or colour separation.

CA looks like this:


This issue was solved in various ways and to various degree centruries ago, ranging from introducing multiple lenses into the optic system, their surface treatment (faceting, coating, etc) and in recent times also digital processing algorythms which are filtering out remains of this nasty.



¯\_(ツ)_/¯

CA has some light usage mostly seen in video editing and perhaps artistic photography, but looking at it in 3D games for extended periods of time might cause increased eye strain, temporary blurry vision, shifted depth perception and general inconvenience to many users.

However, If you read this far the chances are you want to get rid of it already - so without any further ado, let's do this!

CA occurs when ingame PostProcessing quality is set to high or epic preset levels. Turning them off or to medium presets gets rid of CA, but unfortunately it also disables other post processing effects like HDR etc which you might want to keep on.

The way to do it is to edit Engine.ini file which is located at your system drive - most likely C:
The path to it should be like this: C:/Users/YourUserName/AppData/Local/redout/Saved/Config/WindowsNoEditor/Engine.ini

Open it with your prefered text editor and add in the following:

Save it, close it and you are ready to give it a try without CA!

If you happen to have steam cloud enabled, you will get a warning where your local data are not matching saved cloud data - this is normal and to proceed with the changes opt to upload your local data into the cloud, otherwise the change won't take effect and the file will be reverted back to its original state prior to editing.

That's it, simple as that! Although shouldn't it be included in the options natively?!
Anyway, enjoy the considerably less blurry image with no CA at high/epic postprocessing presets.

Hope it helped you and your sore eyes too!

If the image still appears way too blurry, it's because of the anti-aliasing method used ingame. Also it's possible that the AA preset is once again tied to more than just a single effect.

P.S. If there is interest in this topic, I will likely edit and expand the guide in the future.
Now go and rip it up!