Sony A55

With its fundamentally different design, the Sony A55 offers some tempting advantages over other digital SLR cameras -- and a few drawbacks, too, testers say. It's not actually a true digital SLR: The A55 uses a translucent mirror that doesn't have to move as you shoot a picture. This means the A55 can shoot twice as fast as other cameras in this price range -- up to 10 frames per second (fps), beating even the 9-fps Nikon D3S pro camera (*Est. $5,200 body only). It can also autofocus faster, even while shooting video (it shoots in full 1080p HD). Finally, the fixed-mirror design makes the A55 a bit smaller and lighter than its traditional digital SLR rivals. Image quality is similar to the top-rated Nikon D5100 (*Est. $650 with kit lens) in tests -- not surprisingly, as the two cameras share the same 16.2-megapixel image sensor.

But the translucent mirror has its drawbacks. It creates grainier, "noisier" images if you shoot in low light without a flash; experts say they look quite good to the naked eye, but if you look closely, you can see that the camera smoothes out fine details in an effort to quiet the noise. More obviously, the translucent mirror doesn't transmit enough light to allow for an optical viewfinder.

The Sony A55 substitutes an optical viewfinder for an impressively fast live-view mode on the swiveling 3-inch LCD screen, as well as a very large electronic eyepiece viewfinder that experts like -- even better than an optical viewfinder in some ways, as the electronic one includes a lot of useful shooting data. But since you're basically looking at a TV screen, the image sometimes breaks up in low light or fast panning, and it doesn't refresh fast enough to keep up with the vaunted 10 fps maximum shooting rate. The buffer takes a long time to clear after such a fast burst, too -- Dave Etchells at Imaging-Resource.com reports "15 seconds of nothing but a black LCD" during burst shooting. Experts agree that the Sony A55 still outclasses everything else in this price range for burst shooting, but "don't plan on shooting the Olympics with it," as DPReview.com says.

We found the most thorough tests of the Sony A55 at Imaging-Resource.com, DPReview.com, TechRadar.com and DigitalCameraInfo.com. Experts at these websites have the knowledge necessary to critique the camera's unusual design and make its pros and cons easy for novice photographers to understand. Amazon.com posts reviews from more than 50 owners, some of whom have found problems with the Sony A55 that don't show up in expert tests.