The CA is quite a bit easier to get rid of than the coma is, I've written several filters that do it in various ways. I would find the Canon 135mm f2 much, much more useful and the results much more beautiful; but them I'm biased - the Canon 135 has a very strange, magical ability to make people look wonderfully present and human.

Compared to the Sigma the Viltrox is clearly plagued by bokeh fringing, which is absent in the Sigma crops. This is important in bright conditions where a wider aperture could result in your image being overexposed.We use Imatest SFR (spatial frequency response) charts and analysis software to plot lens resolution at the centre of the image frame, corners and mid-point distances, across the range of aperture settings and, with zoom lenses, at four different focal lengths.

We were almost led to believe that Zeiss made a lens where all stops were removed and they came up with something that noone could every surpass.It’s a dream for portraiture and still life, not only due to the quality of the results, but because handling is so refined. By designing the lens from scratch and tailoring it for mirrorless users who desire smaller, lighter lenses, Sigma has created an absolute gem of lens that delivers astonishingly impressive image quality, fantastic lens-based aperture control and complimentary handling all in one. At f/4 and f/8 they are equally amazing with a very slight advantages over sigma which doesn't necessarily excite me.