Sony FE 100mm F2.8 STF GM OSS Review

The hallmark of bokeh effects.

by Sony α Professional Photographer, Chester Chen

Judging by the photos on my Instagram feed, the world seems to be obsessed with bokeh. However, if you want the best tool for the job, you need the Sony FE 100mm F2.8 STF GM OSS. After all, the STF in the model name stands for ‘smooth transition of focus’. This lens is for serious photographers who want the best possible subject isolation, and take their portrait images to the next level.

α7R II 1/125s f/5.6 ISO100 100mm (35mm eq:100mm)

Technically, the Sony FE 100mm F2.8 STF GM OSS lens is an interesting lens with the inclusion of an optical apodization (APD) element. The element cuts out peripheral light rays to deliver magnificent background bokeh in your compositions. It also suppresses chromatic aberrations and increases the sharpness of the image. There is one tradeoff and that is the loss of light. While the lens is listed as an f/2.8 lens, the effect of the APD element reduces the effective light transmission levels to that of an f/5.6 aperture. Not a problem if you are shooting in daylight, using studio lights or increasing the ISO on the capable α7R II or α7S II.

The Sony FE 100mm F2.8 STF GM OSS is a fantastic portrait lens thanks to the way it isolates the face against a sea of creamy background bokeh, one devoid of potentially distracting elements. What the APD element does in this lens is to deliver the cleanest possible background so that the subject stands out clearly – literally popping from the page. That acute separation of the in-focus subject and the smooth blurred background really makes the difference in my shots. Furthermore, with an 11-blade aperture, it produces creamy round bokeh balls – even at the edge of your compositions! The absence of “cat’s eye” or “onion-ring” bokeh is a dream come true for all portrait photographers.

α7R II 1/160s f/5.6 ISO400 100mm (35mm eq:100mm)

Just look at the portrait above. Shot wide open in natural light, the lens draws a flattering image of the model. You can feel the porcelain smoothness of her face and the rendering of her eyes just make them sing! Despite the tightness of the frame and wide-open aperture, the depth of field far exceeds what one would expect.

I love this lens for event photography as I can capture mid-to-close up shots of guests without infringing on their personal space. Thanks to the mid-range telephoto focal length, compact size and modest 700 gram weight, I can leave the bulkier and heavier 70-200mm zoom at home. Attached to the Sony α7R II, it just feels well balanced and well engineered. After all this is a GM lens!

But that is just half the story. The Sony FE 100mm F2.8 STF GM OSS also performs admirably for close-up images. It supports close-focusing down to a minimum focus distance of 0.57m, for 0.25 times magnification. Coupled with 100mm focal length, the wider depth of field at wide-open apertures, it’s easy to fill the frame with gorgeous detail. The lens is also designed to give you fine focusing control. The electronic focusing ring is nicely damped and is able to override the autofocus selection. There is also a dedicated AF focus override button that when pressed, temporarily cancels AF and holds focus until it is released. And it comes with built in Optical SteadyShot^TM that gives me 4-stop protection against motion blur, so getting a sharp image when hand holding is a walk in the park.

α7R II 1/50s f/5.6 ISO800 100mm (35mm eq:100mm)

Just look at the food shot above. It’s so realistic and three dimensional, you can almost reach out and grab it. Again, the APD element makes its presence felt. The texture of the bun is just incredible while the glazed onions feel like they are about to fall out of the frame. All that is set against the realm of buttery smooth bokeh that is so visually pleasing.

α7R II 1/80s f/5.6 ISO200 100mm (35mm eq:100mm)

Speaking of close-up shots, who doesn’t enjoy detailed images of beautiful flowers, so here’s a tulip shot I love. Again, this lens just rocks it. The dewdrops on the soft pink petals look like diamonds on a pillow thanks to their clarity and sparkle. The colourful petals are just bursting with energy too. And there is that magical bokeh again – clean, smooth and isolates the subject perfectly. What is there not to like? A photographer cannot ask for a better bokeh effect.

At $2,259, it may not be a lens that the casual instagrammer can appreciate, but serious photographers will undoubtedly see its worth. This is a lens that must be experienced. The GM philosophy of striking the perfect balance between resolution and bokeh truly culminates into this single lens. With it, you truly have the best of both worlds in the palm of your hand.