I found it.
The Pentax Q 07 Mount Shield Lens (11.5mm f/9) is the final lens in the so-called "Unique Lenses" series for Pentax Q cameras. I already have the Q 03 Fish-eye, the Q 04 Toy Lens Wide, the Q 05 Toy Lens Telephoto.
The Q 07 is an extremely small lens. It is smaller than its rear cap. Moreover, the lens can be used as a replacement of a body cap. That's why it is called the "Mount Shield Lens."
On the Pentax Q (1/2.3"), it is equivalent to a 64mm lens.
It is an electronic lens. It lacks a built-in leaf shutter and aperture control. Therefore, it behaves similarly to that of a manual focus lens with an adapter, with a few exceptions. First, a Pentax Q camera saves EXIF data with lens information (including the permanent f/9 aperture value). Second, a Pentax Q camera recognizes the focal length (11.5mm) for the sensor-shift image stabilization (SR). Third, since the lens lacks a focusing mechanism, it is neither an autofocus nor a manual focus.
The lens has 1 elements in 1 groups. Together with the focus-free design, it produces very specific images. In my opinion, the image quality is the worst in the "Unique Lenses" series. And at the same time, since you don't need to focus, the lens is the most fun to use (for me).
The Pentax Q 07, the Viltrox AF 28/4.5 FE (FF), the Samsung NX 30/2 (APS-C):
See also related notes:
Image albums:
