As well as being Sony's 31st FE mount lens, the new FE 135mm f1.8 G Master short telephoto is also the ninth high-performance GM model, and this series comprises premium-grade – both physically and optically – lenses aimed at both enthusiast-level photographers and professionals.
The optical construction comprises 13 elements in ten groups which includes one special ‘XA’ type (short for “extreme aspherical”) which Sony says employs its latest bokeh simulation technologies in order to “…control spherical aberration and achieve exquisite bokeh”. The optical design also includes ‘Super ED’ and ED glass elements with extra-low dispersion characteristics which are designed to minimise chromatic aberrations and thereby optimise resolution. Sony’s latest ‘Nano AR’ anti-reflection coatings are applied to help reduce both ghosting and flare.
An interesting aspect of the new lens’s optical design is dual focusing groups in a floating focus arrangement to give better close-up capabilities which result in a minimum focus distance of just 70 centimetres and a maximum magnification ratio of 1:4. The autofocusing system uses four of Sony’s proprietary ‘XD’ (‘extreme dynamic”) direct-drive linear induction motors – two for each focusing group – which give increased speed and responsiveness, in particular improving tracking reliability. There is also a new AF control algorithm to maximise response and also ensure quieter, lower-vibration autofocus operation.
On the outside, the new 135mm f1.8 GM lens has magnesium alloy barrel tubes with weather sealing and fluorine coatings on the exposed surfaces of the front element. The aperture ring can be switched between click-stopped and stepless operation, the latter for smoother exposure adjustment when shooting video. The diaphragm has 11 blades to give a more circular opening and smoother out-of-focus effects. There is also a focus limiter switch with three distance range settings and two customisable focus hold buttons. The new lens weighs 950 grams and has a 82 millimetres diameter for fitting screwthread filters. And, talking of filters, Sony is introducing its own range of circular polariser types which will be available in the 49, 55, 62, 67, 72, 77 and 82 millimetre screwthread fittings. They feature a Zeiss T* multi-coating to optimise transmission and minimise flare.
Australian availability and pricing for the Sony FE 135mm f1.8 G Master lens has yet to be announced, but for more information visit http://www.sony.com.au