As one of the company’s G Master lenses, the Sony FE 100mm F2.8 STF GM OSS is designed to produce the highest quality images possible on full-frame Sony E-mount cameras like the A7R II, A7 II and A7S II. However, it can also be used with APS-C format models like the Sony A6500.
According to Sony Europe’s Yosuke Aoki, the main aim for the company’s optical engineers was to combine a high level of detail resolution with attractive bokeh (out of focus areas). Normally a lens that has very high resolving power tends to produce quite harsh bokeh and out of focus highlights have a defined edge.
With this in mind Sony has given the new 100mm lens an apodization element. This is similar to a circular graduated neutral density filter with the denser part being towards the edges. The darkening effectively softens the edges of the bokeh to create more attractive blur.
Including the element effectively reduces the maximum aperture of the lens from f/2.8 to f/5.6. The effective aperture is shown as T-values on the lens aperture ring.
Bokeh is also helped by the 11-blade aperture. While seals around the controls and rings keep out dust and moisture.
In addition, a fast and quiet autofocusing is delivered by the direct drive SSM (Super Sonic Motor) system. There’s also a built-in macro switching ring to enable up to 0.25x close-up capability and Optical SteadyShot image stabilisation to help keep blur from camera shake at bay.
Hands-on Sony FE 100mm F2.8 STF GM OSS review: Performance
We need to shoot more with to test it fully, but my first impressions of the image quality from the Sony FE 100mm F2.8 STF GM OSS are very good. The point of focus has lots of sharp detail while out of focus areas look smooth.
It’s interesting to compare images from the FE 100mm F2.8 STF GM OSS wide open with those from the FE 85mm F1.8 announced at the same time. There are more obvious circles in some out of focus areas in images from the 85mm optic than there are in those from the 100mm lens. The 100mm produces a more uniform blur that looks softer.
Most of the shooting situations that Sony set-up for us to test the lens were quite dark and the autofocusing with the Sony A7R II was a little slow – but still fine for portrait shooting. When the low light was coupled with a model who was vaping, the ‘smoke’ added an extra complication for the focusing and I had a few out of focus images – but that is to be expected.
When shooting outside in heavily overcast (and usually rainy) conditions, the autofocus was pretty fast and accurate.