After the 18-70mm f/3.5-7.1 and 18-55mm f/3.5-6.7 lens patents, Pentax filed another patent in Japan for a 16-55mm f/3.5-5.6 APS-C mirrorless lens:
- Patent: 2012-118431
- Release date: June 21, 2012
- Filing date: December 3, 2012
- Zoom ratio: 3.30
- Aperture: 3.6 - 5.8
- Focal length: 16.22 - 53.51mm
- Image height: 14.20mm
- Back focus: 4.181mm
- Lens length: 72.49 - 86.00mm
- Lens design: 9 lens elements in 8 groups,
- Internal focus