Would you like to see faster medium format lenses being made for medium format cameras? I don't see anyone mentioning this but perhaps we are all quietly thinking it? I'm curious.
What do you call fast, and what do you call medium format?
6*17 is medium format, and I am thinking about the Schneider Fine art Gold 1100 for shift-and-stitch GPX pix... but if you have waves in the picture, and you use a polarizing filter and 50 asa, you need about f4 for 1/125, and the 1100 is f22 with a shutter, or f14 without!
If you do a 400 mm * 170 mm single row shift-and-stitch, (giving you about a GigaPixel) I suppose that would be large format digital?
I have 600 mm and 900 mm aerial lenses with 150 mm front elements (f6) which would be OK wide open using movements without a polarizer... using one shot for the waves and several for the res of the pic.
This is why so many seascapes have "artistically" blurred waves - the photographers did not have the option to do anything else if they wanted DOF without movements.