SG-Image’s New AF 85mm f/1.8 STM Lens

credits: SG-Image

SG-Image, a relatively new Chinese lens maker that has mostly been active in Asia so far, just launched a new AF 85mm f/1.8 STM lens for Sony E-mount. There are also signs that a Z-mount version might be on the way. The lens uses an optical design of 11 elements in 9 groups, including three high-refractive index elements and one low-dispersion element to help control colour fringing. It uses an eight-blade aperture, which should give backgrounds a nice rounded bokeh look.

Physically, the lens comes in at 380 grams, measuring 89mm long with a 71mm diameter, and it takes 58mm filters. The minimum focusing distance is 80 centimeters, with a maximum magnification of 1:7.7, which is about average for this kind of lens. Autofocus is handled by a quiet STM motor, making it suitable not just for stills but also for video work. SG-Image has emphasised the low weight and quiet AF drive as selling points, though since the lens is brand new, there aren’t any independent reviews yet. It will also be interesting to see how it performs when it comes to edge sharpness and distortion once proper tests start appearing.

On the outside, the 85mm f/1.8 STM features an aperture ring and a focus mode switch. SG-Image claims it can handle sensors up to 60 megapixels, which, if true, would make it a decent match even for higher-end Sony bodies. The lens is already available in some markets for around €265 (exchange rate) though it hasn’t appeared at major Western retailers just yet.