Ricoh recently filed a patent in a Japan for a 100-300mm f/4 full frame lens that is most likely designed for the Pentax K-1 DSLR camera. Here are the details: Patent No. 2016-80717 Published on May 16th, 2016 Filing date: October 9th, 2014 Zoom ratio: 2.87 FNO (aperture): 4.1 – 4.1 – 4.1 f (focal … Continue reading Ricoh files a patent for a Pentax 100-300mm f/4 full frame lens