New professional DSLR features 24.6 megapixel full-frame CMOS sensor
The new camera has an extremely impressive specification, with a newly developed full-frame (35.9 x 24.0mm) 24.6-megapixel Exmor CMOS sensor with on-chip analogue-to-digital conversion and two-stage noise reduction, dual BIONZ image processors for ultra-fast operation (5fps at full resolution) and a glass pentaprism viewfinder offering 100 percent frame coverage.
The camera body has a light but strong aluminium chassis with magnesium alloy body panels. It measures 156 x 117 x 82mm and weighs 850g body-only, compared to 1210g for the Canon EOS-1 Ds Mk III or 1240g for the Nikon D3. Viewfinder, card slots, controls and other sensitive areas are protected from dust and moisture by rubber seals. The inside of the camera is also protected by an anti-dust system that protects the sensor from dust entering the body when changing lenses.
The A900 has a new nine-point autofocus system with 10 focus assist points, improved out-of-focus detection to reduce focus hunting, and a dedicated F2.8 sensor for enhanced AF accuracy with wide aperture lenses.
Like other Sony DSLRs the A900 features built-in sensor-shift image stabilisation for which the company is claiming four stops of extra low-speed stability.
Other features include the same ultra-high resolution 921k dot three-inch LCD monitor used on the A700. Unusually for a new DSLR it doesn’t include Live View, but it does have an Intelligent Preview mode which simulates the effect of White Balance, D Range Optimiser and exposure level on the LCD screen without actually taking a picture. Shots can also be viewed on a connected HD television. PhotoTV HD mode provides optimised still image viewing on compatible Sony Bravia televisions. The HDMI terminal also gives access to HD picture viewing on any compatible TV.
The Alpha 900 is the first camera to present a direct challenge to the 21-megapixel Canon EOS-1Ds Mk III and the 12.1-megapixel Nikon D3, until now the only choices for professional photographers looking for a high performance full-frame digital SLR. No price has yet been confirmed, but the Alpha 900 will be launched in October.