How to reduce chromatic aberration on a cheap 420-800mm telephoto zoom lens

Yep, 2 years ago I got my hands on one of those cheap zoom telephoto lenses that are sold under a variety of brands. I thought it wasn't bad for the price, but the chromatic aberration is pretty annoying in some scenes from above 600mm. On the Internet I found the tip with the cardboard ring that is placed on the front lens and is supposed to improve the optical performance of this lens.(For those like me who don't feel like messing around with Photoshop for a long time.) I tried it - with good results. However, the already dim lens loses even more light. In most cases you need a tripod. But if you manage the lens properly, it is fun to take images with it.
I use it on APS-C (canon EOS M50).
Watch my new video, made with this lens:    • More examples of my CA-reduced 420-80...