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Sony launches flagship, full-frame Sony Alpha DSLR-A900
by David Rasnake -  9/9/2008

Sony has announced the launch this morning of their new flagship Alpha DSLR, the full-frame, 24.6 megapixel Sony Alpha DSLR-A900.

Sony Alpha DSLR-A900

Utilizing a proprietary full-frame (that is, the size of a frame of 35mm film) sensor that's been public since PMA in February, the release of this long awaited advanced camera makes Tokyo-based Sony only the third company to decide to play ball in the full-frame camera niche.

As noted, the heart of the A900 is its 35.9 x 24.0mm, 24.6 megapixel Exmor CMOS imager, an in-house development of Sony's semiconductor division. One particularly interesting technical detail of the new sensor, according to Sony, is the way it handles the crucial analog to digital conversion. "Instead of a single analog/digital convertor, the sensor uses over 6,000 on-chip, column-parallel A/D converters to convert analog signals to noise-resistant digital signals at the earliest possible stage," the announcement press release notes. "The result is reduced noise and high-speed transfer of data."

Sony Alpha DSLR-A900
Sony's Exmor full-frame sensor (left), alongside the more common APS-C sized sensor

Sony has opted to couple this high-res capture unit to a pair of its BIONZ image processors, ensuring that speed and responsiveness don't suffer at the expense of resolution. Benefits of the dual processor arrangement are apparent in the A900's continuous shooting speed, with the new camera claiming to be capable of 5 fps continuous-drive image capture.

A normal sensitivity range of ISO 200-3200 on the sensor can be expanded one full stop in each direction, providing the functional equivalent of ISO 100-6400. As with other Sony DSLRs, noise reduction can be fine-tuned to suit individual preferences.

Like all of Sony's current, the A900 uses the Alpha mount inherited from Konica-Minolta, meaning that the new model is compatible with older Minolta and Konica-Minolta full-frame glass. Sony is also rapidly expanding its range of full-frame, high-end Carl Zeiss and Sony G optics. (Note also that digital-only lenses designed for use with APS-C sensor cameras can be used with the A900, but the captures are at a greatly reduced resolution.)

Sony Alpha DSLR-A900

A pair of memory card slots – one each for CF and Sony's Memory Stick format – further expand the A900's flexibility.

An all-new auto focus system is built around nine primary wide-area sensors, with a network of ten "assist points" filling in the gaps between primary areas to provide improved AF response and tracking. A dual cross-type center area sensor is supplemented by an additional system when shooting with lenses faster than f/2.8.

In spite of the fact that Sony currently holds the key to what's arguably the most advanced and functional live view system out there, the manufacturer decided to go in a different direction and eschew live view for their new flagship model. The trade-off makes room in the prism for an ultra-bright pentaprism viewfinder with 100 percent coverage and 0.74x magnification. Given the large number of live view skeptics in the A900's target market, this seems like a well-considered decision. The availability of two user-interchangeable focusing screens (grid and matte variants) in addition the supplied factory default should also make serious shutterbugs happy.

Sony Alpha DSLR-A900

In order to keep the mirror box reasonably compact while accommodating a 100-percent viewfinder and Sony's SteadyShot Inside sensor-shifting image stabilization system (the world's first on a full-frame sensor), the engineering department had to do some fancy work with the A900's mirror motion. The result is a newly designed mirror lift system that uses a parallel link mechanism to move the mirror simultaneously along two axes.

Sony Alpha DSLR-A900

Just because the A900 doesn't have live view, that doesn't mean that the folks at Sony skimped on a screen. To be competitive in the high-end DSLR market these days, a large, extremely high-res monitor is expected, and the Sony brings it with a 3.0-inch, 921K dot "Xtra Fine" LCD panel.

In place of live view, Sony has developed an intelligent preview function that allows shooters to see the effects of settings changes on a final image without taking multiple shots. Press the preview button and the A900 captures a temporary raw image that can then be manipulated on-screen to see the effects of exposure compensation adjustments, white balance changes, dynamic range optimization, and other processing modifications.

Sony Alpha DSLR-A900
Live Preview, Auto White Balance

Sony Alpha DSLR-A900
Live Preview, Tungsten White Balance

Sony has also equipped the A900 with 13 creative picture styles – preset processing options that can then be tweaked to adjust contrast, saturation, and other parameters.

Sony Alpha DSLR-A900

In terms of shooting modes, the A900 is intentionally simple. The basic P/A/S/M options, an auto exposure setting, and three custom positions that allow users to shoot with any desired combination of settings are the only choices. The idea, according to Sony, has been to build a tool for shooters who know their way around a camera, but with an interface that's more simplified and streamlined than the typical professional/semi-pro body.

Sony Alpha DSLR-A900

The A900's physical layout and overall construction is informed by these same principles. We had a chance to get our hands on a pre-production A900, and while we'll have to wait for a production review unit before forming any final opinions, in some initial hands-on time with the new camera we were especially impressed with the device's rugged feeling magnesium shell.

Sony Alpha DSLR-A900

Gasket-sealed buttons and dials provide an additional layer of protection against the elements. The shutter mechanism is also appropriately durable, with a 100,000 click life-cycle.

The A900's optional battery grip, which is also built to the same standards of ruggedness as the camera body, is specially designed with repositioned shutter release and front mode dial controls that sit farther down on the grip, making shooting with the camera in vertical orientation more balanced and natural.

Sony Alpha DSLR-A900

Sony's included Image Data Converter SR3 can be used to process the A900's raw files, providing Sony's Dynamic Range Optimization tool set as well as a Peripheral Illumination control for vignetting correction.

With complete specs finally out in the open, what to make of the A900? The full-frame camera space, which used to be the sole domain of Canon, is quickly becoming a crowded place, but what's most interesting about Sony's entry in our view is the way it has come to market. Sony has assiduously avoiding the word "professional" in favor of a focus on "serious enthusiasts," suggesting a focus with this camera that's slightly different than the approach taken by competitors primarily interested in selling full-frame models to working photographers.

If looks and feel are any indication, Sony has put time and effort into developing a camera that channels the classic film bodies of the past. If some working photographers may find the A900 to be a good fit, Sony sees a potentially larger (and, in many ways, more under-served) market among dedicated photo enthusiasts seeking a serious camera that does nothing from a physical or a functional perspective to get in the way of making images – something that can't always be said of many of the advanced amateur or "prosumer" cameras currently on the market.

With its almost retro-minimalist vibe, the A900 is definitely something different, and should have no trouble distinguishing itself in this space. Whether enthusiasts are ready to fork over the A900's roughly $3,000 asking price remains to be seen, but we'll know soon enough: pre-orders for the new model begin tomorrow.

Sony Alpha DSLR-A900 Specifications:

Sensor 24.6 megapixel, 35.9x24.0mm Exmor CMOS
Lens/Zoom Minolta A-type bayonet mount (Alpha mount)
LCD/Viewfinder 3.0", 921K XtraFine TFT LCD; pentaprism optical viewfinder (100% coverage, 0.74x magnification)
Sensitivity ISO 200-3200 (100-6400 in expanded mode)
Shutter Speed 30-1/8000 seconds
Shooting Modes Auto, Program, Manual, Aperture Priority, Shutter Priority, three custom modes
Scene Presets N/A
White Balance Settings Auto, Daylight, Cloudy, Shade, Fluorescent, Tungsten, Flash, Color Temperature, Custom
Metering Modes Multi-Segment, Center-Weighted, Spot
Focus Modes Wide AF, Spot AF, Local AF; single, automatic, and continuous drive modes
Drive Modes Normal, Continuous High, Continuous Low, Self Timer, Mirror Lock Up
Flash Modes Auto, Fill, Rear Flash Sync, Slow Sync, High-Speed Sync, Wireless
Self Timer Settings
10 seconds, 2 seconds, Off
Memory Formats Compact Flash, Memory Stick
Internal Memory
None
File Formats JPEG, RAW
Max. Image Size 6048x4032
Max. Video Size
N/A
Zoom During Video N/A
Battery Rechargeable lithium-ion battery, 880 shots
Connections USB 2.0, HDMI, PC sync
Additional Features Dynamic Range Optimizer, SteadyShot Inside image stabilization, dual BIONZ processors, Live Preview, magnesium body