Inspired by a demo video of some adapter prototype of others, I decided to dig deeper into Fujifilm's G mount protocol. After a busy weekend's hard working, I finally solved the puzzle. Version 2.0 of the firmware is highly recommended to current adapter owners.
You may get the latest firmware from http://www.fringeradapter.com/#service-and-resources and upgrade your adapter.
Or purchase a C645-GFX adapter with firmware 2.0 from http://www.fringeradapter.com/#buy-it-now
Ver2.0 is significantly improved in following aspects:
1. Recognize different lens models and display aperture correctly
All Contax 645 lenses are recognized correctly. You can control aperture through the ring on lens or the command dial on body. Displayed aperture will be exactly the correct value. Aperture value will be adjusted automatically if Mutar 1.4x applied.
2. No activation required anymore
You don't need to own or borrow a GF63 to activate the adapter anymore. The adapter can be used directly on your GFX50s body with any Contax 645 lens.
3. Full EXIF support
All information recorded in EXIF of JPEG and RAW files is correct. Now you can recall all the exact settings of your camera when you review a photo taken by C645 lens, Fringer adapter and GFX camera.