Fringer C645-GFX II User manual

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Fringer C645-GFX II (FR-C6TG2)
User’s manual
1．Introduction
This product supports C645 mount lenses working on Fujifilm G
mount cameras with electronic aperture control, auto focus and EXIF
recording. Latest firmware and user’s manual can be downloaded from:
https://www.fringeradapter.com/contax-645-to-fujifilm-gfx#3 (en)
or https://fringeradapter.mysxl.cn/#service-c645-gfx (cn)
Lens release
C645 Mount
Micro USB port
for firmware update
G Mount

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2．Compatibility
Camera compatibility: This product supports all G mount cameras in
the market.
1) Cameras with PDAF (e.g., GFX100 and GFX100S): PDAF works. AF
speed and accuracy is relatively better.
2) Cameras without PDAF (e.g., GFX50S, GFX50R and GFX50S II):
Contrast AF only. AF performance is poorer and more error prone.
Lens compatibility: This product supports all C645 lenses. All of them
except Apo-Makro-Planar T* 4/120 support auto focus. All of them
support IBIS when working on cameras with IBIS function, e.g., GFX100,
GFX100S and GFX 50S II).
3．Settings
Lens installation: Align the red dots on both mounts of the lens and
the adapter. Then insert the lens and turn it until the focus indication white
line on the lens is exactly at the top direction and the lens release button
on the adapter pops up.
Full frame/Medium format selection: Please make sure the 35mm
mode is set to Off in the camera menu. If it’s set to On or Auto, the

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pictures may be cropped which isn’t necessary since we are using medium
format lenses.
AF/MF selection: C645 lenses don’t have AF/MF switches. We use
their aperture ring instead. When it’s turned to the minimum stop, i.e.,
maximum F number, the adapter informs the camera to enter MF mode.
Otherwise, it’s in AF mode. The AF/MF switch on the camera can always be
set to AF.
Adapter configuration file: Connect the adapter to a computer
using the cable included. You will see a drive named FRINGER. There is a
file named SETTINGS.INI in the root folder. It’s in standard INI file format.
Don’t modify it unless you understand how to do so. If you want to restore
its content to default, just remove it. The adapter will regenerate a default
version next time when the adapter is used on a camera.
Aperture setting: Aperture may be set through the aperture ring on
the lens. But if it’s in MF mode, the aperture ring is set to the minimum
stop. In that case aperture can be set through command dial on the
camera. Meanwhile, if you set the value of “LensApertureRing=” in
SETTINGS.INI to 0 (the default value is 1), aperture is always set through

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command dial on the camera.
Shutter speed setting: Manually setting shutter speed is
suggested! Setting shutter speed to auto in AF modes may cause the
aperture blades move frequently with noise and flashing of LCD or EVF
when environment brightness changes. That may interfere with view
finding. Be noted, when preview EXP./WB in manual mode in camera
menu is set to Off, you need to use MF mode to avoid the issue.
AF settings: Because of the limitation of the old lenses’ design, AF-S
is suggested. On cameras with PDAF support, e.g., GFX100 and GFX100S,
AF-C may work, too. But don’t expect good performance. On other
cameras, please don’t use AF-C mode. In both cases, Face/Eye AF is
supported. To get a balanced AF performance in terms of success rate and
accuracy, setting focus points to medium size is suggested. Before
releasing the shutter, you may focus multiple times on the same object to
improve accuracy. Meanwhile, please avoid using focus points in columns
close to the left and right edge.
Image stabilization settings: To use IBIS on cameras like GFX100,
GFX100S and GFX50S II, make sure the value of “FocusBracketing=”in

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SETTINGS.INI is set to 0 (the default value). Don’t forget to turn on IS in
camera menu.
Focus bracketing settings: To use focus bracketing, please set the
value of “FocusBracketing=” in SETTINGS.INI to 1 (the default value is 0).
Be noted that please always use AF to set the working range and start
position. If you manually turn focus ring of the lens, focus bracketing
function won’t work properly.
4．Firmware update
You need a PC or MAC and a USB Micro B cable (already included) to
upgrade the adapter.
1. Get the adapter off the camera. Connect it to your computer.
2. Find a new drive named “FRINGER” and copy the new firmware to it.
3. Wait for about 20 seconds. The adapter will disconnect itself and
reconnect automatically.
4. Check the installed firmware version (VERSION.TXT on the adapter)
For example:
Before: