When: 1929 Why: First rollfilm TLR (Twin-Lens-Reflex).
Also it's a first medium format Franke & Heidecke camera. Franke & Heidecke manufactured a couple of stereo TLR camera models before (Rolleidoscop), but again, those were stereo cameras, not exactly suitable for the regular job. Rolleiflex Original was an instant success, and became a parent of many more TLR models which are still produced. You can find detailed specs of this camera on the Rollei Club web-site.