i've had the mk2 for ages.. love the lens and no problems...
I guess 'minimize' is the key word because to me I feel like there is a good deal of chromatic fringing
What type of filter are u using with the lens?
What you're seeing is purple fringing. The lens has no lateral chromatic abberation, but all long lenses suffer from purple fringing except for the Canon supertelephoto lenses and Leica APO lenses. If the lens corrected for purple fringing it would cost $11,000, and weight 3 times as much and be a cousin of the 200-400mm f/4.0 IS TC that's coming out.Just correct it with DXO mark or lightroom. On an related note, I would pay $10,000 for a 200-400mm f/4.0 TC with a wider focal length and faster aperture, say a 70-200mm f/2.0 IS TC