Specifications
Type
D-SLR
Megapixels
16.2 MP
Media Format
Secure Digital High Capacity, Memory Stick Pro Duo, Secure Digital Extended Capacity
35-mm Equivalent (Wide)
18
35-mm Equivalent (Telephoto)
55
Optical Zoom
3 x
LCD size
3 inches
Wireless Connectivity
Yes
HD Video Capture
Yes
Design and FeaturesType
D-SLR
Megapixels
16.2 MP
Media Format
Secure Digital High Capacity, Memory Stick Pro Duo, Secure Digital Extended Capacity
35-mm Equivalent (Wide)
18
35-mm Equivalent (Telephoto)
55
Optical Zoom
3 x
LCD size
3 inches
Wireless Connectivity
Yes
HD Video Capture
Yes
The redesign of the Alpha55's internal mirror box makes the camera a little smaller and lighter than most DSLRs in this price range, like last year's Sony Alpha DSLR A550 ($1,049.99, 4 stars)—it's about the size of Sony's entry-level Alpha 230 ($549, 3.5 stars). Its image sensor is still just as large as traditional D-SLRs (APS-C size), so it will pump comparable image quality out of its smaller body. The Alpha55 measures 3.5 by 4.5 by 2.5 inches and weighs 1.10 pounds; with its default 18-55mm lens attached it weighs 1.57 pounds.
The Alpha55 looks a lot like a Sony D-SLR, and can use all of Sony's Alpha lenses. So what, exactly, is so different about the Alpha55? The answer is all about mirrors. In a traditional D-SLR, there's a moving reflective mirror that passes light from the lens to an autofocus system. Once the image is focused and the shutter release button is fully pressed, the reflective mirror flips up out of the way and the image is passed to main image sensor. Inside the Alpha55, the mirror never has to move—it's the first camera to allow light to pass to the autofocus system and the image sensor in unison. The result is faster focus, and faster shooting in any still or video mode. Also, since there's no part to move back into place, the autofocus system can be re-engaged faster between shots than in a traditional D-SLR.
Unfortunately, the design of the translucent mirror doesn't allow for a true optical viewfinder. The body of the Alpha55 looks like it has an optical viewfinder, but it's actually an electronic one (an EVF), which means it's actually a tiny high-resolution LCD screen (.46-inch with 1.44 million dots) rather than a true viewfinder. In the world of EVFs, this one happens to be quite good—it's bright and sharp. Still, the view from a true optical viewfinder is far more accurate, and I'm not sure the Alpha55's EVF will be an acceptable substitute for everyone. If an optical viewfinder is a must, you'll probably want to pass on the Sony translucent cameras.
If you're not picky about viewfinders, you'll love the incredible, sharp main LCD, measuring three inches and comprised of 921.6K dots. Sony calls it a "TruBlack" LCD—it has excellent contrast and shows virtually no motion blur, so images look fantastic. The display is mounted on an articulating arm that you can pull down 180 degrees or spin on its side 270 degrees—you can hold it above your head or below your waist and still angle the LCD so it's viewable.
Sony's camera interfaces are top-notch, and the Alpha55 is no exception—it's the same UI you'll find on other Sony D-SLRs. Menus are colorful and easy to read, and use fonts, icons and navigation similar to the Xross Media Bar found in Sony's PS3 and HDTVs.
Speed and Still-Image Performance
In my tests, I found that the Alpha55 can power on and capture a shot in an average of 1.3 seconds. In continuous shooting mode it was even faster, firing 6 frames per second. To compare, the Editor's Choice D-SLR Canon EOS T2i ($899.99, 4.5 stars), was able to shoot just 3.4 frames per second. Like a true D-SLR, the Alpha55 has no shutter lag. The Alpha55's best trick, though, is that refocusing between shots is much faster because there's no waiting for the mirror to move into position. If you're shooting multiple photos of a moving subject, you'll have a much better chance keeping it consistently in focus with the Alpha55.
In the lab we use Imatest to objectively measure image quality. After measuring 50 spots through the frame, the camera had a very good center-weighted average of 1,981 lines per image height at ISO 100 (2,054 in the center, 1,967 part way to the corners and 1,729 in corner regions), though the Canon T2i's score was a little sharper at a center-weighted average of 2,296. According to Imatest, if there is more than 1.5 percent noise in an image, the noise will become visible; the Sony Alpha55 was able to keep image noise below 1.5 percent up to ISO 6400. That's an excellent result, and means you'll be able to take sharp images in poor lighting environments without a flash.
Video-Capture Performance and Conclusions
Video recording on the Alpha55 is another big selling point; it's simple to operate and the results are excellent. The Editors' Choice Canon T2i takes a few seconds to autofocus during video recording, whereas the Sony Alpha55 takes a fraction of a second thanks to the translucent mirror. Also, the Alpha55 continuously focuses during video recording, so it can keep faces in focus. Operation feels just like a camcorder. Because it has a larger image sensor, the video quality is superior to any consumer camcorder or pocket HD Camcorder, like the Flip Ultra HD 8GB ($199.99, 3.5 stars). Video footage was sharp with little noise and beautiful colors.
If you just want simple video recording, you'll find the Alpha55 easy to use, but there's a problem: the lenses aren't silent. This is a problem with all D-SLRs. Every time the lens refocuses or you zoom in and out, you'll hear the lens move. The camera does include an external microphone input, so you can purchase an accessory mic to bypass the internal microphone's audio and avoid the noise from the lens. Sony does make silent lenses, but they are only compatible with the Editor's Choice Sony NEX-3.
Those more versed in video recording might be deterred by the lack of professional recording features. The Alpha55 offers no control over shutter speed or aperture while recording video, so you can't control how much blur is in each frame or the depth-of-field. Also Single-Focus AF (only autofocusing once the shutter is press halfway) is not available while recording video, just continuous AF or manual focus. This can be a problem when the camera shifts focus when you don't want it to. If Single-Focus AF was offered, the camera would only autofocus on command.
Videos can be recorded in two file formats. The lower-quality, Web-friendly MP4 codec captures 1440-by-1080 high-definition video at 30 progressive frames per second, with a bitrate of 12 megabits per second. If you use the higher-quality AVCHD codec, you can use a higher bit rate, larger resolution and faster frame rate (17 megabits per second, 1920-by-1080 at 60 interlaced frames per second).
Built-in, industry standard mini-USB and mini-HDMI ports easily connect the Alpha55 to a computer or HDTV for image or video playback. The camera's memory card reader accepts SDHC/SDXC cards (up to 2TB) or Memory Stick Pro Duo (up to 32GB). The camera is powered by a rechargeable InfoLithium battery.
If you're looking for a lightning-fast shooter that can pump out D-SLR-quality still images and video, and you won't miss an optical viewfinder, don't hesitate to get the $849.99 Sony Alpha55 (SLT-A55VL) or its less-expensive sibling, the 14.2-MP Alpha33 ($749.99 with 18-55mm lens). With these cameras, you'll get speed you just won't find in a D-SLR. But if you can't do without an optical viewfinder, stick with the Canon EOS T2i or the Nikon D3100 ($699.95, 4 stars), which is the only D-SLR to offer video recording with continuous focus (though it's not nearly as fast as the continuous AF offered by the Alpha55). If size trumps speed on your wish list, the Editor's Choice Sony Alpha NEX-3 offers D-SLR-quality images in a much smaller camera.
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