Similar to Nikon, Pentax filed a patent for a high-powered zoom lens DA*25-350mm F3.3-5.6ED [IF] SDM:
- Patent application: 2011-8234
- Release date: 01/13/2011
- Filing date 05/22/2009
- Focal length: 25.71-339.99mm (13.22 zoom ratio)
- Aperture: 3.3-5.7
- Angle of view: 4.8-60°
- Image circle: 28.48mm
- Back focus: 52.92-108.59mm
- lens length: 174.86-281.04mm
- Internal Focusing