Does anyone know why this happens?

[ZacFreeland]

This isn't my full image. I just cropped a little out because this is where it's most noticeable. Take a look please.

Does this happen to anyone else? The pink and green highlights some time stick out so much, I just throw the picture away.

I shoot with a Canon 7d with this lens: HERE and I also use a circular polarizer at all times. I also shoot and edit with RAW. Is this normal or might there be something wrong?

Thanks for looking!

 

[KmH]

It is called Chromatic Aberration (CA). Chromatic aberration - Wikipedia, the free encyclopedia

All lens have CA to some degree. CPL filters also come in varying levels of quality and a low quality CPL could add to the issue.

 

[Garbz]

Should also mention that CA varies with zoom level and aperture. Most lenses exhibit worst CA at extremes. Such as the Nikkor AF 80-200 f/2.8D has very bad CA at 200mm f/2.8 but is perfectly acceptable at 80mm f/2.8 or 200mm f/4

 

[analog.universe]

Also worth mentioning that certain lenses (read expensive) correct for CA to the point where it's barely noticeable.

In any event, CA is a predictable physical phenomenon and there are various tools for Photoshop, GIMP, etc that will allow you to remove it pretty decently.