Sony Moves Up the Performance Ladder
By Ron Eggers
The The Sony Alpha DSLR-A700 is a solid piece of equipment that combines strong performance with affordability. I reviewed the Sony’s original DSLR, the A100, and liked it, and the A700 is a step up. It has a higher-resolution sensor, is more responsive and feels better built. The rugged magnesium alloy body is quite heavy for its size, yet its ergonomic grip and well-balanced proportions are comfortable for shooting.
Though it’s not marketed as a pro camera, the A700 is more of a professional model than a consumer DSLR. Take its responsiveness, for example. There's no focusing hesitation or shutter lag. It responds on demand. And the camera pretty much lives up to its 5-frames-per-second (fps) capture rating. Using a high-speed Extreme IV 2 GB CompactFlash card, shooting in the Hi continuous advance mode, and without repositioning or refocusing the camera during the burst, it was possible to capture 17 to 18 frames per 4-second burst. That's good performance.
The A700 is designed around a new APS-C size CMOS Exmor Sensor with effective resolution of 12.2 megapixels, and maximum capture resolution of 4,272x2,848 pixels. Captures are processed through the advanced Bionz image processor with hardware-based, large-scale integrated circuitry, which Sony has refined to increase performance, speed processing, optimize image quality, and significantly reduce electronic noise.
As you’d expect in a serious camera, the A700 can capture images in the RAW file format. It’s also got cRaw, a compressed raw file format a high-end file format option that’s not available with most pro DSLRs.
There are noise-canceling routines built into both before and after analog-to-digital conversion, making it possible to shoot from ISO 100 to ISO 6400, a greater range than some pro models. There are no noise problems in the lower ranges. At ISO 1600, electronic noise is still minimal. Noise becomes noticeable at ISO 3200 and, as you’d imagine, a problem at ISO 6400.
One way of keeping down the ISO is to use the camera’s built-in Super SteadyShot Image Stabilization. The sensor responds to correct for any camera shake, so stabilization is available with any lens attached. Stabilization makes it possible to pick up two, even three stops without having to crank up the ISO. Like the A100, the A700 takes lenses with the Minolta A-mount, including the millions of Minolta lenses already in use and the new Carl Zeiss lenses being developed specifically for the Alpha line. There's a 1.4X lens conversion factor. The review unit shipped with the DT 16-105mm f/3.5-5.6 Wide-Range Zoom lens.
Exposure is controlled through a 40-segment honeycomb sensing system. When metering in the multi-pattern mode, the system factors in all 40 segments to make the exposure.
More and more DSLRs include a shooting mode designed to bring out detail in over- or underexposed images. The A700's version is Dynamic Range Optimization. There's the standard DRO mode, which improves image detail in the underexposed areas through standard gamma curves; the advanced auto mode, which includes five DRO correction levels; and DRO advanced bracketing, which automatically writes three versions of the captured image with discrete DRO levels with a single release of the shutter.
Above: 1/500 second at f/10, ISO 400, no Dynamic Range Optimization. ©Ron Eggers
Above: 1/500 second at f/10, ISO 400, maximum Dynamic Range Optimization. ©Ron Eggers
There are noticeable differences in the exposure when you adjust the DRO. In fact, the difference between shooting with DRO off and shooting at the maximum DRO is quite noticeable. Detail in heavy shadow is increased significantly and the highlights don't get washed out.
Focusing is relatively fast. For auto focusing, the A700 relies on an 11-point Center Dual Cross AF Sensor system. You can let the camera select the focus points automatically, or set them manually. The focus drive clutch speeds switching between auto and manual focusing. With its special Eye-Start autofocus system, the camera actually starts focusing as soon as your eye is positioned near the eyepiece, before you even touch the shutter or any other button.
Left: Open shade, 1/60 second at f/9, ISO 200. Right: Bright sunlight, 1/320 second, f/7.1, ISO 200. Model: Shawnna Martinez holds the title of Young Miss Corona (the city, not the beer). ©Ron Eggers
There are also three custom white balance slots, which the camera calls registries. Setting custom white balance couldn't be easier. A button on top of the body displays the white balance menu on the LCD. Then just scroll down to the custom option, using the navigation multi-selector dial on the back of the body. Scrolling right or left brings up the custom setup menu.
When that menu is accessed, you're instructed to shoot one frame. The screen that comes up indicates the current color temperature in the active registry on top, and the color temperature (to the closest 100K) of the just-captured scene on the bottom. You can scroll through the three registries to find an empty one or one that can be overwritten, so when the right registry is displayed, the captured color temperature information will write to that slot. Any of the three registries can be recalled as needed. That's easy.
Like most digital SLRs, the A700 comes with a series of built-in scene modes, portrait, landscape, macro, sports action, and sunset. Each mode can be fine-tuned for your personal preferences.
Many of the frequently used controls, such as ISO, white balance and the drive mode, are directly accessible through specific buttons on the body. Then there's the custom (C) button. Any one of 15 functions can be assigned to it and brought up instantly. Some of those functions, including ISO and white balance, have their own buttons, so I'm not sure there’s an advantage to assigning them to the custom button. On the other hand, some control commands, such as to format memory cards and changing memory card slots, that should be directly accessible, can't be assigned to the custom button.
The camera takes both CompactFlash and MemoryStick Pro removable media, but does not support automatic card sensing. You have to go into the menu every time you change the card type. Most DSLRs with two card slots store captured images to the whichever slot there's a card in, without your having to assign the slot. If there’s a CF card in the camera and you start firing with the MemoryStick slot designated, it won't work.
Fortunately, there is a way to set the menu so that the last menu item accessed comes up first. But you do have to wade through multiple menu pages if you've done something else since, like format a card.
The bright 3.0-inch TFT LCD is viewable in most lighting, even from extreme angles, to the point that if you can still see the surface of the screen, you can generally see the picture on it. One handy little feature, when the camera is placed at eye level and the LCD information screen is on, the screen goes dark so the eye doesn't get distracted.
The entire camera operating environment, including exposure settings, metering options and color temperature preferences, can be saved into one of three memory registries. Twenty-eight parameters, ranging from the recording mode and image quality to focusing and exposure setting, can be stored. Accessing each of those registers loads the entire slate of stored settings.
To keep the sensor clean, there's anti-dust vibration that automatically shakes the sensor to dislodge dust every time the camera is turned off.
The camera ships with a wireless remote. A vertical grip is available as an option. The A700 body is priced at $1,399.99. Kit versions are also available.
Sony Alpha DSLR-A700 Specs
SENSOR: 12.2 megapixel CMOS Exmor Sensor
RESOLUTION: 4272 x 2848 pixels
IMAGE PROCESSOR: Bionz processing engine
LENS FOCAL LENGTH CONVERSION: 1.4X
METERING: TTL metering. 40-segment honeycomb-pattern SPC - Multi-segment, Spot & Center weighted
SHOOTING SPEEDS: (Rated) - 5 frames per second
ISO: 100 to 3200 (6400 available as expanded ISO range)
EXPOSURE SETTINGS: Auto, Program AUTO (with Program Shift), Shutter-priority, Aperture-priority, Manual, Scene selection (Portrait, Landscape, Macro, Sports action, Sunset, Nightview/portrait)
SHUTTER: Electronically controlled vertical-traversefocal-plane shutter with electronically controlled speeds, 1/8,000 to 30 sec. X-sync at 1/250 sec.
WHITE BALANCE: Auto, Daylight, Shade, Cloudy, Tungsten, Fluorescent, Flash, Color temperature, Color filter, Custom
VIEWFINDER: Fixed eye-level with optical glass pentaprism. Approx. 95% coverage.
LENS MOUNT: Sony a / Minolta A-tyep
FLASH: Manual pop up
STORAGE: CompactFlash Type I & II, MemoryStick Pro