Fujifilm surprised us at Photokina 2016 when it announced a medium-format system, but was short on details at the time. Hasselblad was first with a mirrorless interchangeable-lens medium-format, the X1D-50c, but the Fujifilm GFX 50S and its lenses are not only a lot more affordable, but it seems to look and operate a lot more like the mirrorless cameras we're used to.
The camera and the first three GF-series lenses are slated to ship in February. The body will go for a reasonable $6,500; the GF63mmF2.8 R WR lens is $1,500, the GF32-64mmF4 R LM WR is $2,300, and the GF120mmF4 Macro R LM OIS WR is $2,700. (I don't have pricing for other regions, but those directly convert to roughly £5,290 for the body and £1,220/£1,870/£2,200 for the lenses in the UK, and AU$8,625 for the body and AU$1,990/AU$1,350/AU$3,580 for the lenses in Australia.)
Later this year, Fujifilm plans a GF110mmF2 R LM WR, GF23mmF4 R LM WR and GF45mmF2.8 R WR. (To get the 35mm-equivalent focal length for reference, multiply the lengths by 0.77.) The company will also offer an adapter so that you can use lenses from its GX series of film medium-format cameras.
The GFX 50S is the first camera back in the system, incorporating a new Fujifilm-designed sensor that's close to the resolution and size of the X1D-50c's -- 51.4 megapixels, 43.8 x 32.9mm 4:3 at a 5.3 micron pixel pitch. Note that it's not an X-Trans CMOS sensor, Fujifilm's technology which uses a nonstandard color filter array. Instead it's a typical Bayer CFA CMOS. It does incorporate the same imaging processor as the most recent X-Trans cameras, though, the X Processor Pro.
The body is dust and weather sealed, with coldproofing down to 14 degrees F/-10 degrees C. Unlike Hasselblad, which puts the shutter in the lenses, Fujifilm puts a focal-plane shutter with a maximum speed of 1/4,000 second in the body, though the camera also offers an electronic shutter up to 1/16,000 second.
It will come with an electronic viewfinder that attaches in the hot shoe, and there'll be an optional multiangle adapter to use with it.
Size-wise it seems about the same and weight as the X1D.