If you're a bokeh fanatic, you're probably always chasing those wide aperture lenses to get that smooth, out-of-focus look that makes your subject pop against the background. But, you might be surprised by the beautiful bokeh you can get from a lens that only has an aperture of f/2.8. Check out this great video on a fascinating lens.
Coming to you from Miguel Quiles, this interesting video takes a look at the Sony FE 100mm f/2.8 STF GM OSS lens. STF stands for "smooth transition focus," and it refers to the presences of an apodization element in the lens. An apodization element is essentially a radial neutral density (getting darker toward the edges) that sits near the aperture inside the lens. The effect of this is much smoother bokeh, though at the cost of lower light transmission (thus the reason the lens only behaves like an f/5.6 when it comes to light-gathering ability). Nonetheless, if you can account for the lower light-gathering, you can get some incredibly smooth bokeh — smoother than a lot of lenses with wider apertures. They're quite interesting lenses; check out the video above to see the sort of results you can get from one.