A "medium format Noctilux" 100 mm f/2 lens that covers the 53x40 mm IQ4 sensor by onasj (see previous posts by Onasj):
As my previous posts have hinted, I love hand-held ambient-light photography for its nimbleness and broad applicability. Indeed, one of the reasons why I made the jump from Nikon/Sony/Leica 35 mm systems (all excellent in their own ways) to medium format was to take advantage of the *theoretical* low-light, high ISO advantage of the larger sensor and, especially, of the current-generation of back-side illuminated (BSI) medium format sensors that Sony has manufactured. Among medium format cameras, currently these sensors are in the Phase One IQ4 (53.4 x 40 mm sensor, 151 MP), and the Fuji GFX-100 (44 x 33 mm, 102 MP). As I previously documented (https://photorumors.com/2019/01/20/m...ne-comparison/), the BSI sensor architecture in the IQ4 offers substantial (~1 full stop) of high-iso signal:noise advantage over the IQ3, consistent with what Bill Claff measured (Photographic Dynamic Range versus ISO Setting). In addition, the BSI sensor minimizes the need for color correction when shifting or tilting, a major benefit for technical camera use.
