The Samyang shows no distortion. Illumination is fairly even from corner to corner at f/2 and narrower apertures. But at f/1.4 there is a some noticeable dimming at the edges (-1EV) and at the corners (-1.5EV). It's not dramatic and can be compensated for easily using software tools. Regardless of the brand name and barrel style, the optics are the same. And Samyang sells the 85mm for every major camera system. You can get it for Canon, Four Thirds, Nikon, Pentax, or Sony SLRs, as well as for Canon, Fuji, Micro Four Thirds, Samsung, and Sony mirrorless cameras. The Nikon version of the lens, which we received for review, supports electronic aperture control, but other mounts only support mechanical aperture control. The lens is not optically stabilized, but it's not a feature that's usually found in 85mm prime lenses. Samyang describe this lens as a 'Portrait lens', which may explain some of the characteristics of its optical performance. At f/1.4 sharpness in the centre of the frame is only fairly good, and towards the edges, 'dreamy' would be a good way of describing the clarity here. This is all well and good for flattering a portrait subject, but not for much else. Stopping the lens down improves clarity across the frame, but the sharpness towards the edges still lags way behind that of the centre until around f/8. Peak sharpness across the frame is achieved between f/8 and f/11.

Optical construction is 11 elements in 8 groups, including 4 HR (High Refractive Index) and 1 ED (Extra Low Dispersion) elements. UMC coating is Samyang's own version of Ultra Multicoating. There are 9 blades in the diaphragm, to assist in producing smooth bokeh; the quality and gradation of the out of focus areas in an image.Build quality is excellent. The lens has a metal housing and a metal mount too. The optical elements are made of high-grade glass and aspherical lenses have been included to minimise aberration and unnecessary light dispersion. The focusing ring is pleasingly wide and ridged for easier grip.

Sharpness is good rather than insanely great at f/1.4, while defocused areas look beautifully soft and dreamy (Image credit: Matthew Richards) The build quality of the Sigma 85mm F1.4 DG DN Art is on par with the Sony GM and above the Samyang and Sony FE85mm F1.8 Le Sigma 85mm F1.4 DG DN Art et le Sony GM sont les meilleurs en terme de bokeh et de flou d’arrière plan F1.4 F2 mis focus eye af F4 F2 F2.8 F4.5 F1.4 F2 F4 F1.4 F2.5 F4 2.2 Vignetting , chromatic aberrations , distortion, flare, sunstars Falloff of illumination towards the corners is typical of a fast aperture lens like this. The corners are 2.28 stops darker than the image centre at f/1.4 and visually uniform illumination is achieved by f/5.6.Focusing is usefully internal and manual focusing is possible when the MF mode is set on the Sony camera body. Full-time manual focus override is also available if you choose the DMF focusing mode instead. There's no distance and/or depth of field scale available on this lens. The new Samyang has a fast , quiet and precise AF in most cases but it still has occasional issues with eye AF and in burst mode for difficult subjects (see dedicated chapter). The Sigma 85mm F1.4 DG DN Art has the best autofocus of the 85 F1.4 , very similar to the Sony FE85mm F1.8