Like the 40D, Sony supplies a compressed raw format, cRaw, designed for faster raw-format burst shooting, in addition to its various combinations of standard raw and JPEG files. Unlike Canon's spatially compressed--that is, lower resolution--sRaw, however, Sony's cRaw uses lossless compression to shrink file size from about 18MB to 12MB. On one hand, cRaw does let you shoot about 7 more frames in a burst (more, but not faster).
In-camera processing algorithms also get a boost. Sony's Dynamic Range Optimizer, which applies image adjustment curves to expand the tonal range, now offers an advanced mode that analyzes 1,200 segments in the frame. In addition, there's a DRO bracketing drive mode. In a similar vein, the A700 ships with seven Creative Styles, which are named presets of combinations of contrast, saturation, sharpness and brightness: Standard, Vivid, Neutral, AdobeRGB, Portrait, Landscape, and Black and White. Of those, the last three support user adjustments and add a Zone setting option, which can automatically adjust the tonal range for high-key (bright) or low-key (shadowy) scenes. For a complete list of these and the camera's more mundane features and operation, check out this PDF version of the user manual.
By the numbers, the A700 delivers very good--though not outstanding--performance for its class. (CNET Labs ran the tests using the 18mm-to-70mm kit lens.) It can shoot 0.5 second after power up, the same amount of time it takes to focus and shoot a typical well-lit scene, and two consecutive nonburst shots edges up to 0.6 second. These results put it about 0.1 second behind the 40D overall for single shots, though in practice I didn't feel much of a difference. The responsive feel may be attributable to the overhauled focusing system, which uses 11 area AF sensors, 2 each horizontal and vertical line sensors in the center plus an f/2.8 sensor to improve focus speed when shooting with a wide-aperture lens.
However, like many of its competitors, under dim, low-contrast conditions, the A700's focus slows, bumping the lag to 1.2 seconds; though common, I still think that's still too long for cameras at this price. Though it can't match the 40D's 6.3 frame-per-second (fps) burst-shooting rate, the A700's 4.8fps acquits itself quite nicely, especially since I think the focus matches its speed better than the 40D's does at maximum. (Sony's rating of 5fps assumes use of a UDMA-capable CF card; we obtained 4.8fps with a SanDisk Extreme IV, which is non-UDMA.) In field tests, I was quite happy with the A700's continuous-shooting performance.
As for nonquantifiable performance measures, Sony says it's enhanced the SteadyShot stabilization system--not the optical version, but the sensor-shift mechanism inherited from Konica Minolta--and claims it can buy you as many as four stops. It has a new gyro, with claimed improved compensation for high-frequency motion, such as overcaffeinated hands. Mine qualify as a moderate case of the high-frequency jitters; in bright light it delivered on the four-stop promise and in low-ish light gained me about 2 2/3 stops, both using manual focus.
Like the Nikon D300, the A700 also sports a somewhat confusingly specced 921,600-dot/307,200-pixel LCD with an approximate 170-degree-rated viewing angle. It's quite a nice display, viewable in bright light, and surprisingly good for judging sharpness when you're zoomed into a photo at the camera's 13x maximum.
The A700 incorporates Sony's latest 12-megapixel CMOS chip. Unlike most other sensors, this new model performs its analog-to-digital conversion on-chip, rather than in the imaging pipeline, a practice which Sony claims delivers better control over image noise. Though I can't confirm or deny that this is a better technology, the A700's noise profile is quite good. It does an excellent job maintaining color and exposure consistency across all the ISO sensitivity settings, and photos are quite usable up to and including ISO 3,200. Beyond that, as with similar cameras in this class, color speckles and smeary details begin to crop up.
All in all, I'm very impressed by the Sony Alpha DSLR-A700 as an all-around midrange digital SLR. Though more expensive than the Canon EOS 40D, the built-in image stabilizer and higher resolution are worth the extra bucks, unless you really need the little extra oomph in continuous-shooting performance that the 40D delivers.
(Shorter bars indicate better performance)
|Time to first shot||Raw shot-to-shot time||Shutter lag (dim light)||Shutter lag (typical)|
(Longer bars indicate better performance)