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Mamiya’s ZD Digital Capture
Back
Medium-Format Digital Capture on a ‘35mm’ Budget
by Allan
Weitz
Nobody doubts the value of medium-format imaging – be it digital or film -
when your assignment calls for images sharp enough, and detailed enough, to take
them up to billboard-size, or reproduce in the glossiest of publications. The
problem up till now has been cost of medium-format capture backs, which for many
shooters has been somewhat formidable.
With the introduction of the Mamiya ZD Digital Back - a 22 megapixel capture
back designed to work with Mamiya’s 645 AFD, 645 AFD II, and RZ 67 Pro IID
camera systems - cost concerns are hereby null and void. The bottom line is you
can now afford to offer your clients more bang for their buck without having to
mortgage the farm.
The Mamiya ZD Digital Back is geared towards portrait, still-life,
architectural photographers, and others requiring image files that can stand up
to close scrutiny regardless of where and how they are reproduced.
Pixel count aside, it’s important to include bit-depth and dynamic range into
the equation when discussing what makes the ZD Digital Back a serious imaging
tool. Current full-frame (24x36mm) DSLRs capture 12-bit color, which consists of
4096 discernable shades of gray. The Mamiya ZD Back captures 14-bit image files,
which can produce up to 16,536 shades of gray, or four times the volume of tone
produced by your ‘35s’. The net results for you are sharper image files
containing far more robust color and tone.
In terms of tonality and detail it would be fair to compare image files from
the Mamiya ZD and the leading 35mm-based, full-frame DSLRs to comparably exposed
film transparencies from a quality 35mm camera and a comparable medium-format
film camera. Both cameras will produce fine results, but the medium-format image
will contain far more detail in the shadows and highlights, smoother tonal
transitions, and better overall sharpness as compared to the 35mm image.
The 22Mp CCD sensor used in the Mamiya ZD22Mp is a ‘nit’ smaller - 36x48mm -
than the frame size of its 645-format film counterpart. A black hairline that
runs about 1/8" along the edge of the camera’s viewfinder defines the ’live’
area of the frame. For all intent and purpose, the 1.16x crop factor matters
little when choosing the best focal length lens for the job.
The Mamiya ZD digital back can be programmed to record image files as RAW
(about 34Mb), JPEG (9 compression levels, 0.8 to 10Mb), or RAW and JPEG
simultaneously. Images can be recorded to CompactFlash (CF Type I/II) or SD
memory cards with processed image files opening up to a bit over 61Mb. Images
can be captured in burst-rates up to 10 frames at 1.2 frames-per-second.
For viewing and editing your images, the ZD back features a 1.8” Polysilicon
TFT Color LCD that displays 100% of the image area. The screen can be programmed
to display shadow and highlight warnings, a histogram, as well as a slideshow of
everything recorded on your card. For checking focus, a Zoom button located on
the camera’s back panel allows for 4x, 9x, or 16x magnification of the captured
image.
The set-up menus feature icons with text descriptions, and are easy to
navigate without need of an owner’s manual. Camera control buttons are equally
easy to decipher and use. The Mamiya 645 AFD IIs viewfinder is bright, and the
lenses tested focused quickly and accurately. As with all current medium-format
AF cameras, there is only one, centrally located AF sensor, which means if your
subject is off-center in the frame you have to pre-focus on your subject,
depress the shutter halfway down, recompose your shot, and shoot, or switch to
manual focus.
The ZD back records images in either Adobe RGB or sRGB. White balance options
include Auto, Daylight, Overcast, Shade, Fluorescent, Tungsten, 2 presets, as
well as Kelvin, which can be manually set from 2800 to 10,000K in 100K
increments. ISO ratings on the ZD back can be set from a native ISO 50 up to ISO
400 in 1/3rd-stop increments.
A particularly useful feature of the 645ZD is the ability of the end-user to
install an optional low-pass filter, which helps reduce or eliminate moiré
patterns that occasionally rear their ugly heads when shooting clothing and
textiles. Low-pass filters, which are built into most all DSLRs, also reduce the
‘jaggies’ that often appear along curved lines. The downside of low-pass filters
is that in the course of correcting these phenomena, they also reduce sharpness.
With the new ZD back you have the option of installing a low-pass filter as
needed to suit the assignment.
Included with the ZD is a copy of Mamiya’s PhotoStudio software, which allows
you to adjust exposure, focus, metering, ISO, as well as fire the shutter from
your computer keyboard. To help organize your images as you go through your
workday Mamiya also includes a copy of Adobe Lightroom, which along with
Photoshop CS3, can be also be used to open and manipulate Mamiya RAW files.
The new ZD digital back can be purchased as a stand-alone back or as a kit,
which includes a Mamiya 645AFD II body, a ZD back, and an 80/2.8 AFD lens. So if
you’ve been hankering to step to the next level, Mamiya just made it a whole lot
easier, not to mention affordable, to enter the medium-format digital arena. If
you already own a Mamiya 645AF or RZ Pro IID system, the ZD back can be viewed
as an opportunity to squeeze additional mileage out of your existing gear for a
very reasonable price.
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