2
work like native GF lenses. The earlier firmware versions required an avatar lens to make the
camera body accept the adapter. That led to many problems. A GF63 was needed to activate the
adapter. Aperture was not displayed and recorded correctly. And all Contax lenses were
recognized as GF63/2.8. Now, with the latest firmware, all the above issues do not exist anymore.
You don’t need to find a GF63 and activate the adapter. Lens model, aperture and focal length are
all displayed and recorded correctly (except the focal length of 45-90. See the next sector for
details.)
3.
Aperture control and Exif recording
There is a built-in aperture ring on Contax 645 lenses similar to GF lenses. However, there is
no ‘A’ and ‘C’ on that ring. We use the
smallest stop
on C645 lens’ aperture ring to
simulate
the
C
stop
of GF lenses. For example, for C645 140/2.8 lens there are F2.8, F4.0, …, F32, i.e. totally 8
stops, on its aperture ring. When you turn that ring to F32, the aperture is controlled by the
command dial of the camera body. When you turn the ring to other stops, the position of the ring
decides the aperture directly.
In contrast to the previous versions of firmware, now the aperture and focal length
information are all displayed and recorded correctly. See the following table for details.
Contax 645 lenses
Max aperture
Correct aperture
on LCD/EVF and
in EXIF
Recorded focal
length
Correct focal
length in EXIF
Distagon T* 3,5/35
F3.5
Y
35mm
Y
Distagon T* 2,8/45
F2.8
Y
45mm
Y
Distagon T* 3,5/55
F3.5
Y
55mm
Y
Planar T* 2/80
F2.0
Y
80mm
Y
Apo-Makro-Planar T* 4/120
F4.0
Y
120mm
Y
Sonnar T* 2,8/140
F2.8
Y
140mm
Y
2,8/140 + Mutar1.4x
F4.0
Y
196mm
Y
Sonnar T* 4/210
F4.0
Y
210mm
Y
4/210 + Mutar1.4x
F5.6
Y
294mm
Y
Tele-Apotessar T* 4/350
F4.0
Y
63mm
Y
4/350 + Mutar1.4x
F5.6
Y
490mm
Y
Vario-Sonnar T* 4,5/45-90
F4.5
Y
45mm
N
(1)
(1): So far the real focal length of zoom lens 45-90 is not recorded correctly. It always be
45mm. This issue may be solved in the future version of the firmware.
4.
AF/MF selection and aperture priority
There are two working modes, i.e. AF and MF.
4.1
Lenses with AF support
To enter AF mode, turn aperture ring to any position other than the smallest stop while
camera is off or in playback mode. Then, power on the camera or turn back to the shooting mode.
Meanwhile, make sure the AF/MF switch on the camera is at AF-S position. To enter MF mode,
just turn the aperture ring to the smallest stop and make sure the AF/MF switch on the camera is