The Contax 645 represents the second AF medium format SLR currently on the
market. It competes directly with the Pentax 645N and Mamiya 645 AF (to be
released in October, 99) and is currently the only AF medium format SLR to
feature an interchangeable viewfinder and a filmback. The use of Carl Zeiss T*
lenses presents another appealing feature.
Communication between the lens, body, filmback, and viewfinder is exclusively
electronic. Electronic linkages do away with mechanical wear and tear and provide
design and expansion flexibility. One example is the possibility of leaf-shutter
lenses in the future. (All current Contax lenses are shutter-less and utilize the
focal plane shutter in the camera body.)
A new metallic shutter assembly
The Contax utilizes the first medium format metallic-blade shutter. The
shutter is electronically controlled and has a top speed of 1/4000s, which is
another first for medium format.
There are three filmbacks currently available for the Contax: Standard,
Polaroid, and Digital.
For Standard, two inserts are offered. The regular insert accommodates both
120 and 220 film types by rotation of the pressure plate. The Vacuum Film Insert
is a Contax exclusive. It is also used on the Contax RTS III. A mechanism creates
a vacuum during the moment of exposure and keeps the film flat on the pressure
plate. This theoretically increases focus accuracy and provides sharper pictures.
Unfortunately the Vacuum Film Insert works only with 220 films due to
interference of the backing paper on 120 films.
The standard viewfinder is the AE prism finder with center-weighted and spot
metering options. A waist-level finder is available.
Unlike the Mamiya and the Pentax, the Contax uses in-lens motors. The AF
system doesn't have an AF-MF clutch and hence allows for simultaneous AF and
Additionally, the AF system uses a high precision area sensor for enhanced
accuracy. This will be discussed in greater details.
1/125s flash sync and TTL pre-flash metering
The Contax offers the fastest flash sync of 1/125s for focal plane shutter
medium format SLRs. Also available is the TTL pre-flash metering feature which
works with ANY flash equipment. This handy feature is well described in the
Contax RTSIII review here on photo.net.
The camera prints exposure data on film outside the picture area.
Film Barcode Reader
The Contax is one of a few medium format cameras to have this feature. The
reader scans the barcode on DX-coded film and sets the film speed automatically,
just like on most 35mm cameras.
Built-in Motor Drive
The Contax advances film at the rate of 1.6 frames per second. That's slower
than the Rollei 600x and Pentax 645N, but faster than all other systems
The Carl Zeiss T* lens line up comprises roughly the fastest medium format
lenses in each focal length range. The 120mm/F4 lens is the only APO Zeiss
Makro-Planar currently available, and is allegedly the best of the Makro-Planars.
This life size macro lens is the only manual focus lens in the lineup.
Build Quality and Ergonomics
Although the Contax has a plastic outer shell, it is a very well built camera.
The chassis is made of rigid copper silumin like the RTSIII, while the body
covering material is a mixture of polycarbonate and carbon fiber. Carbon fiber,
which is the same material used to build F1 racecars, maximizes the body's
ability to absorb strong impact while keeping the weight at a minimum. The result
is a respectable reduction in weight--with all the extra features, with batteries
loaded the Contax weighs the same as the Pentax 645N. The same setup on a
Hasselblad, which I have tried, would make the Hasselblad far too heavy for rapid
shooting. The unique texture of the outer shell also makes the camera quite
scratch-resistant. My Contax once landed on gravel (prism finder first) from a
five-feet height . All I got was very fine rub marks. The body feels solid with
excellent grip comfort and weight distribution.
The control layout theme is basically the same as the RTSIII, which uses
mostly dials and levers than buttons. Most notable is the Contax-style AE Lock
switch, which locks the exposure EV value for as long as the switch is engaged.
By flicking the switch, one is free to experiment with framing without having to
worry about losing the metered value after some period of time as on most
In practice I find dials and levers to feel a lot more accessible and
reassuring than buttons.
Certain less frequently used dials need to be unlocked before they can be
turned. I find this approach to be finicky and unnecessary at times; it's not
always easily done if you have large fingers, and some of these dials are quite
well protected where they are that the locking/unlocking feature is
One feature that Contax could have thrown in is to automatically open the
shutter when the filmback is taken off--this will prevent the shutter blades from
being damaged by accident. But since the Contax is entirely electronic, this
feature can be added with a ROM upgrade in the future. For the time being, a rear
body cap that comes with the camera body is available if you want to be on the
On the other hand, the Contax does have many smart additions to prevent
mistakes. For example the filmback cannot be taken off unless the dark slide is
in place and fully inserted, and the shutter won't fire unless film is loaded.
(You can, however, test fire the shutter without film if you remove the filmback
altogether.) And I find more of these thoughtful designs as I use the camera more
On balance the build quality of this camera is outstanding and unique, and the
ergonomics are very good but can definitely be improved.
The Contax's AF is slightly quieter and faster than the Pentax 645N (which I
owned for a while until stolen). But that doesn't put the Contax in the same
league as the top 35mm AF SLRs.
To generalize, AF on the Contax is less noisy than Canon's non-USM lenses, but
obviously not as quiet as those with USM. Focusing from closest to infinity takes
a bit of time, but sufficiently fast for most situations in practice. I haven't
had a problem with AF speed on either the Pentax or the Contax.
The Contax system uses in-lens motors and rear/inner focusing whenever
possible. So why is AF not blazingly fast?
First of all the Zeiss lenses are heavy. The Zeiss lenses for the Contax don't
weigh any less than those for the Hasselblad and have the same manual focus feel.
They all have stainless steel barrels and very solid construction, which , in the
case of the Contax, come at the expense of AF speed.
The second reason, according to Contax in an interview with Asahi Camera
magazine of Japan, has to do with AF precision. Contax has made a firm commitment
to take precedence in image quality, and this commitment prompted them to produce
an AF system that optimizes precision rather than speed.
According to Contax, they have optimized AF precision on three levels. Most AF
SLRs on the market use a small number of linear or cross-type AF sensors, usually
in a horizontal formation. Each sensor is made up of a few hundred pixels. The
Contax 645 is the first AF SLR to use a 1/4 MILLION-pixel CCD for its AF system.
The result is a true area sensor (i.e. no gap) with supposedly much higher AF
measurement accuracy. Secondly, the AF motor in each lens is optimized for
precision with extremely fine movement rather then speed. Lastly, in the case of
220 type films, the vacuum filmback ensures higher film flatness.
How much better is the resulting AF precision is not known without some
testing, but there are indeed some compromises as a result. The AF motors being
optimized for precision, comes short in speed as I said. Also, the choice of 1/4
million-pixel CCD, which means a lot more information needs to be processed,
slows down AF a little more and adds to battery consumption. (This has been
verified by Asahi Camera.)
Whether the tradeoff in speed is worthwhile is beyond me. But if I were Contax
I would throw in a provision to switch off the area sensor to function in a
single point focus mode and add a second AF algorithm to optimize speed over
precision. This way the user can decide between speed and precision on his or her
own. (I wonder if this can be achievable via a future ROM upgrade.)
On the other hand, the Contax 645 AF-MF integration is the best I have seen.
Basically AF and MF can work simultaneously without the need to switch between
focus modes; the camera is constantly ready to operate in both AF and MF. This
allows you to fine tune the focus manually at any time. For example, if you turn
the MF ring during autofocusing, the AF motor stops to allow focus manually. AF
can be reactivated at anytime by half depressing the shutter release. In
practice, the ability to shift rapidly between AF and MF is very handy. Also, AF
activation and AF lock can be assigned to a dedicated button, instead of being
fixed to the shutter release button. In my opinion, the AF-MF integration is
similar to the Canon real-time manual focus concept, but is one step further.
Exposure Modes and Metering
Being targeted at professionals and serious amateurs, the Program mode is
absent on the Contax. No protest from me. All the other basic modes--aperture
priority, shutter priority, full manual, bulb--are provided.
Metering is very accurate and consistent. With the prism finder, TTL
center-weighted and spot metering options are available. Unlike the majority of
medium format cameras, spot metering is still available with the waist-level
finder (but not center-weighted metering).
The spot metering circle is concentrated and is marked in the viewfinder.
Pre-flash TTL metering is, in my opinion, the best of its kind on the market.
Again please refer to the RTSIII review for details on this feature.
Asahi Camera measured the aperture accuracy to be between +/- 1/8EV
approximately. The shutter speed is within +/-0.02EV accuracy. This level of
exposure precision is very high and hardly achievable with a mechanical camera
with a cloth shutter.
The prism finder is bright and uncluttered. Viewfinder information provides
just the information that you need and is easy to read, although the 645N's is
slightly better. There is a focus confirmation light, which is handy if you
choose to focus manually. The same display is available when a waist-level finder
is in use, which has not been the case with other cameras that I've used. The
prism finder also features an eyepiece shutter and a built-in diopter.
Changing the focusing screen is easy. No tools are necessary. The focusing
screen has a steel frame with a small handle for holding by fingers and is glass
laminated on one side to prevent fingerprints and damage, especially when a
waist-level finder is used.
The optional microprism collar/split-image focusing screen is not very good.
The central circle looks brighter than the surrounding area, and the microprism
doesn't provide that in-focus snap. There is at least one third-party
manufacturer with a replacement screen planned.
Against the Pentax 645N and Mamiya 645AF
Modeled with a 35mm SLR in mind, the Pentax 645N lacks an interchangeable
filmback which renders digital photography impossible. (The Contax already has
digital backs available.)
The Mamiya has an interchangeable back and functions a lot more like the
Contax. However, like the Pentax the Mamiya doesn't have a interchangeable
viewfinder. And both of these cameras use a in-camera motor for AF and require
the use of a switch to go between AF and MF. In other words, they don't offer the
AF-MF integration of the Contax.
One additional strength of the Contax is its TTL pre-flash metering, which
makes studio photography extremely easy.
On the other hand, the Mamiya has an additional active AF system for shooting
in a dark environment. There is a visible red light emitter on the body. (Contax
claims that they chose to not include this feature because of the short useful
distance of only 4 to 6 feet.)
The Mamiya has partial backwards compatibility with current Mamiya 645 lenses.
The lenses can be used, but need to be stopped down for metering.
The standard Contax kit contains the body, an AE prism finder, a standard back
(with insert), and a 80/2.0 lens at $4,000. The closest Hasselblads (with
electronic linkages and focal plane shutter) are the 200 series bodies. A 203FE
body alone costs about $5,000, and is over $8,000 by the time you add a prism
finder and a motor drive. And this price doesn't include a standard lens. The
Contax seems like an absolute bargain in comparison.
On the other hand, the Contax system is much higher priced than the Mamiya
645AF and Pentax 645N. The bodies are priced similarly, but lens-wise the Contax
costs quite a bit more. Ultimately, Zeiss lenses carry a premium, and the Contax
system offers several features and flexibilty not available on the other two
systems, namely an interchangeable viewfinder. Also the Contax lenses are
generally faster and much better built.
The higher price may also reflect the small production volume--the Contax 645
is produced in very small quantities of 1,000 units per month for all the markets
combined, according to a Contax press release. In my area, these cameras don't
ever stay on the shelf for long.
The Contax represents a milestone in medium format photography. It garners
several world firsts in its design and features, and has a high quality of
construction. It is arguably one of the most flexible medium format camera
to-date, with capabilities, thoughtful additions ,and portability that allow it
to fill the job of both a 35mm AF SLR and a medium format SLR. On the other hand,
its shortfalls are AF speed and some minor ergonomic nitpicks. There is room for
improvement, but for the time being it remains the most advanced and functional
system on the market.
Where to Buy the Contax 645
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