I was using the ISO 12233 Resolution Chart Comparison tool and noticed that many Nikon lenses versus their Canon equivalents show quite a bit more purple fringing at wide apertures. Like for example the Nikon 85 1.8G vs. the Canon 85 1.8. Is this a characteristic of Nikon lenses? Is it a testing artifact? Do Canon lenses just not have purple fringing wide open? I know different companies focus on different performance aspects but this seems excessive.....