I see these type of CA all the time with my 24-70L. I'm very sure that you're not along with this and it's not an issue of the lens. I also see the same type of CA on the Sigma 50/1.4 and my 85/1.8 lenses. I'm not sure about the theory behind it, If you see Bryan's review about the 85/1.2L II going through a focus calibration on the 1Ds III body here (go down the page until you find the section), the same type of CA occurs when the lens is not well in focus. I assume this is just an optical property, nothing serious to worry about.


As long as the CA does not appear at the point where the image is sharp on focus, I personally don't really care.