"Other compromises are wavy mustache-type distortion, very strong chromatic aberration (CA) and strong purple fringing in high contrast edge transitions around bright areas. But, all of these can be corrected in post. Adobe Lightroom version 4, which includes a profile for this lens, is effective at correcting all of these problems. Point light sources towards the edges will reveal strong coma smearing wide open, mostly gone by f/4 and appears to be gone around f/8." 其实暗角和红移都不是什么大问题。图像处理软件(Cornerfix?)可以修正。 M9自己的 firmware也可以修正。Corner smearing就比较难了。 A7在广角的corner smearing确 实比Leica严重。 但是这是一个数码全幅的common problem, 真正要解决我觉得必须从 sensor design入手。 目前我觉得富士在这领域还是领先的: http://petapixel.com/2013/06/11/fuji-and-panasonics-new-organic