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There are a dozen interchangeable-lens digital SLRs in production as of this
writing, all but one adapted at least in part from their manufacturers’
film SLR cameras. The exception is Olympus’s new E-1, which was designed
to be digital from the ground up. The thinking behind this is that an entirely
new design can be optimized for digital photography in all areas.
The Four Thirds System
Basing a digital SLR on an existing film camera does provide a few advantages:
You don’t have to start designing from the ground up, your photographers
will have a degree of familiarity with the camera body, and your photographers
can use their existing arsenal of lenses. But there are disadvantages, too.
For one thing, while film’s silver-halide grains can accept light striking
them at an angle, digital sensors need the light to hit them pretty much straight
on; thus digital SLRs based on cameras designed for film produce images that
tend to be unsharp and darkened at the edges, especially when wide-angle lenses
are used (in fact, minimizing this is one reason why the image sensors in many
adapted-from-35mm-SLR digital cameras are smaller than a full 35mm film frame).
For another, there’s no open standard: Brand A bodies take Brand A lenses,
Brand B bodies Brand B lenses, and that’s that.
The new Four Thirds system was created by Olympus and Kodak (with Fujifilm also
signing on) to solve these and other problems. By establishing standards for
the diameter of the image circle and lens mount (the latter being approximately
twice the former), and the lens-mount-to-image-plane distance, the Four Thirds
system assures that all Four Thirds-system cameras can use all Four Thirds-system
lenses, no matter who makes them. (This isn’t a huge factor right now,
as the E-1 and its four lenses are the entire Four Thirds system at the moment—but
the system developers hope to see this change before too long.)
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new Olympus E-1 is an excellent general-purpose digital SLR, designed
and built for working pros, two of whom shot the images at left
and below with the camera. The rugged full-featured body accepts
4/3-system lenses. |
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For the record, the Four Thirds standard specifies a 4/3-type image sensor
with a 4:3 aspect ratio and a diagonal dimension of 22.5mm, making for a chip
measuring 18x13.5mm, considerably smaller than a 24x36mm 35mm film frame. This
smaller sensor size allows for special designed-for-digital lenses that send
the light to the chip in a more straight-in path. It also allows for much smaller
and faster lenses—the 300mm f/2.8 Zuiko Digital telephoto lens for the
E-1 produces an image framing equal to that of a 600mm lens on a 35mm camera,
yet is much smaller—and a stop faster—than 600mm lenses for 35mm
cameras.
The E-1 uses a 5.5-megapixel (5.0 effective) Super Latitude Full Frame Transfer
CCD from Kodak. Traditional interline CCDs move data via a “highway”
on each pixel that takes up space that could be used for image capture. Full
Frame Transfer CCDs move data via a vertical “highway” that takes
up a lot less space, leaving more of the pixel area for image capture—1.5X
more, in the case of the E-1’s sensor. This results in more light-gathering
ability, a higher signal-to-noise ratio, a wider dynamic range, and better resolution.
Additionally, the 4:3 aspect ratio closely matches the aspect ratio of conventional
8x10 and 11x14 prints (and magazine covers), so photographers don’t have
to crop out 17% of the image to fit such media as they do with the 3:2-ratio
35mm-format images produced by other digital SLRs.
The E-1
The first thing that struck us about the new E-1 is that this camera is a magnificent
piece of gear mechanically. If you like rugged, precision devices, you’ll
love the new Olympus E-1. Fit and finish, control operation...this camera reeks
of quality. It’s splashproof and dust resistant, and even provides a solution
to that bane of interchangeable-lens digital SLR users, dust on the imaging
sensor: there’s a built-in Supersonic Wave Filter between the shutter
and the sensor that uses high-speed ultrasonic vibration to make most types
of dust fall away.
Inside this amazing rugged body is a new High Speed 3 ASIC (Application Specific
Integrated Circuit) processor that provides speedy image processing, interface
processing and camera control. The body itself is more compact than film-camera-based
digital SLRs, measuring 5.6x4.1x3.2 inches, and weighing 23 ounces. It fits
the hand well, and the control placement and operation are well thought out.
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Hand-held existing-light shot of aquarium fish was made in full-auto
mode, 1¼8 at f/3.5. |
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Focusing
Featuring a three-point (center, left and right) TTL phase-contrast AF system
that functions in light levels from EV 0–19 (there’s also an AF
illuminator that assists dim-light autofocusing, and can be cancelled when desired),
the E-1 will automatically select the appropriate AF point (the one containing
the closest subject), or allow you to select any point manually. The three-point
AF wasn’t functional on our pre-production test camera, so we used center
AF, and found it very quick and accurate even on moving subjects like birds
in flight. A lever near the lens selects single-shot AF, continuous predictive
AF, and manual focusing modes. You can (via the LCD monitor menus) select whether
the camera will permit you to shoot in single-shot AF mode before the camera
has focused, or whether the shutter locks until focus has been achieved. You
can also select whether you can fine-tune focus manually after autofocusing,
or not; and the direction the lens rotates to focus from near to far to suit
your preference. You can even choose whether the focusing ring is activated
with the camera switched off, via the monitor menus.
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