The Chinese company Kase, which specializes in filter technology but has expanded to lens manufacturing, has given photography enthusiasts an unauthorized look at its future REFLEX 150mm f/5.6 autofocus lens, which is to be released for the Sony E-mount, specifically for the full-frame format. The announcement was first made on the Sony Alpha Rumors website on the 24th of January, 2026, which was then documented on the Asobinet website on the 27th of the same month. The lens is a catadioptric, or mirror reflex, lens, which means that the lens has a mirror to reduce the overall size of the lens. This could potentially be the most compact lens of its type, a 150mm lens, in the world. 

Specifications of the Kase REFLEX 150mm f/5.6 Autofocus Lens

- Focal length: 150mm, which is roughly equivalent to a 225mm lens on APS-C format sensors.
- Aperture: Fixed aperture of f/5.6, which is typical of reflex lenses.
- Autofocus: Full autofocus support, which could be a world first for a reflex lens.
- Mount: The lens is to be released on the Sony E-mount, although there is speculation about a future Nikon Z-mount release, as well as a Fujifilm X-mount release.
- Filter thread: The lens has a 67mm filter thread.
- Other features: Autofocus/manual focus switch, full-frame support.

The lens, as shown in the unauthorized leak, is a very compact lens, cylindrical in shape, which is much shorter and lighter than a traditional 150mm telephoto lens. Reflex lenses, which use a mirror instead of a refractive lens, allow for a much more compact lens, although there are some drawbacks, such as the bokeh, which is often a donut shape, a loss of contrast, a loss of sharpness, and the lens being a fixed aperture.

Kase already has a range of manual focus reflex lenses, such as the 200mm f/5.6, which are offered in a variety of mounts such as Sony E, Canon RF, Nikon Z, and many others. These are ideal for creating unique bokeh effects that are often desirable for artistic and creative purposes. These are also relatively affordable within the range of $500-$750. The addition of autofocus to this type of reflex lens will greatly improve its usability for subject tracking such as birds, sports events, or other applications where telephoto reach is important without the burden of a larger and heavier lens.

As mentioned, “This compact 150mm doesn’t exist elsewhere,” and while the lens might not be able to compete with the best refractive telephoto lenses currently available, the compact size might make it a desirable choice for travel or everyday super telephoto shooting. This marks the second autofocus lens from Kase, having previously released the 85mm f/1.4. This suggests a broadened strategic approach within the optics market.

Currently, no official release date, price, or other details have been announced; this information has yet to be confirmed. However, it is suggested that users wait for official announcements from Kase. Nevertheless, the discussion also reflects the continued development and innovation from Chinese manufacturers within relatively untapped markets.