Kase’s 150mm f/5.6 Reflex Lens Is Here

credits: Kase

The previously reported Kase 150mm f/5.6 reflex autofocus lens is now officially here. What makes the lens interesting is that it combines a mirror (reflex) optical design with autofocus, something you do not see very often. It is launching for Sony E-mount and Canon EF mount, with the possibility of additional mounts later on. Another more unusual feature is the magnetic front ring, which allows filters and the lens cap to attach magnetically instead of relying only on traditional screw threads.

The optical design uses five elements arranged in four groups, following the folded light path typical of reflex lenses. That design helps keep the lens relatively compact compared to traditional lenses with a similar focal length. The lens has a fixed f/5.6 aperture, a minimum focusing distance of 1.5 meters, and supports both autofocus and manual focus. It is designed for full-frame cameras, and the optical layout tries to reduce chromatic aberration while still producing a characteristic bokeh-look.

Physically, the lens is relatively compact for a 150mm. The Sony E-mount version measures about 82 × 105mm and weighs around 529 grams (about 554.5 grams with the hood). The Canon EF version is slightly shorter at 82 × 82mm and weighs roughly 487 grams (around 512.5 grams with the hood). The lens supports 67mm filters, including both standard threaded filters and the magnetic filter system. It also includes an AF/MF switch and a textured focus ring for manual adjustments.