From megapixels to viewfinders to sensors, size matters.
What happens when an electronics behemoth jumps into DSLRs? In Sony's case, it pushes development into overdrive for a couple of years. Then it makes a full-frame 24.6MP CMOS sensor and steals the title of most megapixels in the 35mm format from Canon, which has held the title for as long as anyone can remember.
But a camera is more than just megapixels. And the Alpha 900 ($3,000, street, body only) packs a gorgeous viewfinder that covers the entire frame, plus real-world resolution greater than that of any camera we've tested.
In terms of design, the A900 follows previous Sony DSLRs. The grip has a deep cutaway for your middle finger and a long divot on the inside for your fingertips, making a very comfortable hold. There are dual scroll wheels to set shutter speed and aperture independently, plus dedicated buttons for exposure compensation, white balance, ISO, and drive mode, as well as a dial for exposure mode. Add the fact that you can press the function button to jump into a menu of most of the settings, and you've got a really versatile imaging tool.
Like too many pro-level DSLRs, the A900 doesn't pack a pop-up flash. Ask Sony, though, and you'll hear that the A900 isn't meant for pros. We doubt that'll stop wedding and event photographers from flocking to it. That goes doubly once they check out Sony's new HVL-F58AM flash ($500, street). Since the entire flash head swivels horizontally instead of twisting, you can keep the head in the same basic position for vertical portraits as for horizontal shots. So, while the white bounce card in most on-camera flash units faces in the wrong direction when you shoot verticals, it faces your subject with this Sony.
IN THE LAB
Color? Not as accurate as most pro-level DSLRs -- though, with an average Delta E of 9.0, it ranks Extremely High in our rating. Also, while noise remained at Very Low and Low through ISO 800, it rose to Moderately Low territory at ISO 1600, hit Moderate by ISO 3200, and reached Unacceptable at the top sensitivity of ISO 6400.
Resolution? Excellent across all ISOs. It was best at ISO 100, with 3230 lines. For comparison, Canon's 21.1MP EOS-1Ds Mark III ($7,500, street, body only) scored 2830 lines and Nikon's 12.3MP D700 ($2,700, street, body only; $3,375 with 24-120mm f/3.5-5.6G ED-IF AF-S VR lens) turned in 2350 lines in the same test.
As we've seen before, Sony's noise reduction eats up a lot of resolution. But, since the A900 has resolution to spare, the result isn't bad. At ISO 800, the camera delivered 3010 lines. At ISO 3200, that number dropped to 2630 lines and by ISO 6400 it was 2440 lines -- still more than the Nikon D700's top resolution. Keep in mind that even though the Sony has resolving power at that high ISO, you will see noise in the image, so the overall image quality rating drops.
Nonetheless, the Sony maintained an Extremely High image-quality score at ISO 3200 and Very High at ISO 6400. At ISO 100-1600, it was rated Excellent.
Though the A900 has just 9 selectable AF points and 10 assist points to boost their sensitivity, autofocus was very fast in bright light, focusing in 0.29 sec at our test's brightest level of EV 12. AF took less than 1 second down to EV -1, slightly brighter than the light of a full moon. At our dimmest level of EV -2, AF still didn't quit, though it slowed to 1.42 sec.
That makes it very competitive with the Nikon D700, whose autofocus started at 0.35 sec at EV 12 and slowed to 1.25 sec at EV -2. Nikon has an edge in coverage, thanks to 51 AF points that reach further left and right in the frame.