I bought 70-200 f/4 IS and it seems to me that it suffers from purple fringing. I have never used this lens before so I am not totally sure if this is acceptable level or not. I sent this image to Canon support and they said it's 'within product specification'. I still can return it and I would really appreciate your opinion.

Full image (f/4 70mm):

Personally I don't even see any purple fringing in the 2nd image, the first does display a fair bit, but what you've got to remember is that that image is worst case scenario, wide open with extremes of contrast.

Having said that I don't recall ever seeing anything like that with my copy.

Chris

check out this thread too. http://www.fredmiranda.com/forum/topic/642420

Are there any lenses which perform perfectly in extreme worst-case scenarios?

I am almost convinced that if you shoot the same scene on film, you wont be able to see that fringing. No wonder some people refer to that as "sensor bloom".

Thank you for response. I do not see any purple fringing on the second shot either. I posted it as it looks sharp to me.
I understand this is an extreme case but the amount of the PF seems much bigger than in this shot below from another copy of this lens. A salesperson in the store suggested that using some -1/2EV should help a lot with this. I can't try it today though.

Same f/4 70mm but almost no PF: