The TTArtisan 500mm f/6.3 was just announced and can be preordered from B&H Photo and Amazon in E/Z/RF/L Mount. The lens is a manual lens that kind of looks like the Hasselblad 500mm TeleTessar f/8 and the TTArtisan 500mm f/6.3 is coming to X and GFX in the future according to a discussion on Weibo between TTArtisan and a user in their comments. This could be a great value for GFX owners that shoot telephoto since the Hasselblad 500mm has gone up in price over recent years and can be hard to find in good shape in my experience purchasing 3 of them over the years.
