Sony Alpha DSLR-A100K

Sony has debuted its DSLR-Alpha 100K—popularly referred to as the Alpha 100—a full-featured, 10.2-megapixel digital SLR with removable lenses and built-in shake reduction technology. Though Sony is a late arrival to the DSLR market, the Alpha 100 is an excellent first offering that immediately gives the electronics giant a strong foothold in the marketplace.

Built with technology acquired from now-defunct Konica Minolta, the Alpha 100 sports Minolta’s signature Maxxum lens mount, making it compatible with the huge array of legacy Minolta lenses. Sony has re-branded the mount’s name to Alpha Mount and also announced 19 new Sony lenses (many of which are based on existing Minolta lenses). So, though Sony is new to this market, it comes out of the gate with an SLR that has high-level technology and an impressive array of lenses.

Priced at $900 for the body plus an 18-70mm lens, the Alpha 100 sits at the high end of the entry-level market. With its all-plastic body and smooth finish, you certainly won’t mistake the feel of the camera for a higher-end model. Nonetheless, the camera is sturdy and creak-free. The Alpha 100 is small for an SLR—about the same size as the Canon Digital Rebel XTi (   )—but it is light and comfortable to hold.

The Alpha 100 also packs a full set of features including priority modes, full manual mode, program modes, and scene modes. Like most entry-level DSLRs, the Alpha 100 lacks a dedicated status LCD screen, opting instead to use the camera’s main 2.5-inch LCD monitor. I prefer a dedicated screen, ideally top-mounted, but the Alpha 100 has a nice feature in that, when the screen is on, if you place your eye on the viewfinder, the screen immediately shuts off, and powers up again when you take your eye away from the viewfinder. Like most entry-level DSLRs, you adjust features using a combination of buttons and simple menus on the camera’s main LCD screen. While this scheme is not as elegant as dedicated external buttons, configuring the camera is as speedy and easy as any of its competitors.

In addition to the features that you’d expect (and want) from an SLR—ISO speeds of 100 to 1600, easy access to exposure compensation, program shift feature, and Raw format support—the Alpha 100 has some extra niceties. In addition to the normal autofocus mechanism, the Alpha 100 has a continuous autofocus mode that constantly focuses as you move the camera around. For shooting in rapidly changing environments, this improves the camera’s chances of being in focus when you’re ready to shoot.

Continuous autofocus mechanisms have been around for a while, but Sony has improved the mechanism by adding an eye sensor. If you’re not looking through the viewfinder, the camera doesn’t bother trying to autofocus. In addition to conserving battery life, this keeps your camera from grinding and whirring as you carry it around. The Alpha 100’s autofocus is very noisy, and produces strange clunking and grinding noises while you’re using it. If silent operation is important, this may not be the camera for you.

Like the Pentax K100D (   ), the Alpha 100 offers a sensor-based stabilization system, which Sony says yields 3.5 stops of stabilization. I found it to be closer to 1.5 to two stops—still a welcome feature, but not as impressive as the lens-based stabilization offerings from Canon and Nikon. The sensor-moving stabilization system also serves as a dust-removal system, but the Alpha 100 wisely activates the dust-removal cycle only when you turn the camera off, giving you faster startup times.

The camera is a good performer, offering speedy boot-up and wake-from-sleep, and very low shutter lag. The Alpha 100’s drive mode is speedy for this market, offering three frames per second for six frames when shooting raw, and unlimited drive mode when shooting JPEGs, which lets you shoot until your card is full.

Sony has wisely opted to use CompactFlash technology for the camera’s storage, rather than its own MemoryStick. However, current owners of MemoryStick Duos can buy a CompactFlash adapter that will let them use their current media in the camera.

When shooting at ISO 100 to 400, image quality is very good–comparable to anything else in this market. At 800 to 1600, the Alpha 100’s images get noisy, falling behind the Rebel XTi and the Nikon D80 (   ) in image quality. Overall, though, you won’t be disappointed in image quality for most situations.

Macworld’s buying advice

The Sony Alpha DSLR-A100K is a very good camera, albeit a little pricey. While it feels clunkier than its competitors, it delivers very good image quality and a full feature set, as well as some nice extras such as image stabilization. While Sony has released a good selection of lenses for the Alpha 100, its lens collection is fairly expensive when compared to the digital-specific lenses from Nikon, Canon, and Pentax. The Alpha 100 is a good competitor to the Canon Rebel XTi and the Nikon D80, but you should get your hands on all three to get a feel for their interfaces and grips before making a decision.

[ Ben Long is the author of Complete Digital Photography, 3rd Edition (Charles River Books, 2004). ]