Sony DSLR-A330 Optics

Sony A330 Optics

The Sony A330 features a bayonet lens mount, which accommodates a range of Sony and Konica Minolta lenses. The Sony A330 comes bundled with a Sony 18-55mm f/3.5-5.6 SAM kit lens. A separate kit comes with both the 18-55mm and a 55-200mm f/4-5.6 telephoto zoom lens. A small button on the front of the camera releases the lens from its mount, so it can be turned and removed. The A330's CCD is smaller than a 35mm frame, so the angle of view at any given focal length will not be the same as on a 35mm camera. To find the approximate 35mm equivalent focal length, multiply the focal length of the lens by 1.5. (Thus, a 50mm lens will provide about the same view as a 75mm lens on a 35mm camera.)

The Sony A330 provides both manual and automatic focus control modes, set by the Focus Mode switch on the left side of the camera body. You can select between Auto and Manual focus modes. The Function button provides access to additional AF modes and AF Area options. The Autofocus Mode option under the Function menu offers Single-shot AF, Automatic AF and Continuous AF settings. Single-shot sets focus with each half-press of the Shutter button, while Continuous mode is constantly adjusting the focus, whether the Shutter button is pressed or not. The Automatic setting will lock focus on a still subject or continually adjust focus on a moving subject, for as long as the Shutter button is halfway pressed.

Autofocus Area also has three options available through the Function menu: Wide, Spot, and Local (manual setting). The default option is a nine-point Wide Focus area, indicated by an array of square focus areas inset within four widely-spaced brackets in the viewfinder image. (Note that only the center point utilized a cross-type sensor sensitive to detail in both the horizontal and vertical axis. The other 8 sensors are line-type, sensitive to detail in one direction only, although the four line sensors at the corners of the AF array are angled, so they'll respond to both horizontal and vertical detail.)

You can override the chosen AF mode by pressing the Spot AF / OK button in the center of the Multi-controller on the camera's rear panel, which defaults to the more accurate center AF point (the latter indicated by a target box in the center of the viewfinder). Wide AF bases its focus on the most prominent subject detail in the portion of the image that falls within the AF brackets. Spot mode bases its focus on the very center of the frame, where the square target resides. The Local setting is Sony's terminology for a manual AF area selection, and lets you manually set the main AF point by using the Multi-controller to highlight one of the nine AF points. The active AF area is briefly illuminated in the viewfinder.

Sony didn't include a depth-of-field preview button on the A330, nor on any of its new consumer models announced early 2009. Admittedly, that feature is less useful with such a small viewfinder, but this factor might put off some macro and landscape photographers.

Sony A330 AF Assist

The Sony A330 uses its built-in flash head as a very bright AF-assist light for better focusing in dim lighting. This has the advantage that the light from the flash is very bright, but the downside is that you can only get AF assist when the flash head is raised. This is a real limitation for available-light photography, as the camera can expose at light levels well below those it can focus at. (Although its low-light focusing ability is much better than average.) If the camera is fixed on a tripod, you can work around this limitation, but it's somewhat awkward: With the flash head up, half-press the shutter button to make the camera focus. Then switch the focus mode to manual focus, being careful not to touch the focus ring on the lens. Stow the flash head, and then take your picture. (But don't forget to switch back to AF mode for the rest of your shooting!)

Sony A330 Anti-Shake

The Sony A330 also employs Sony's Super SteadyShot anti-shake technology, which uses a highly sensitive accelerometer and Smooth Impact Drive Mechanism (SIDM) to move the CCD assembly itself to counteract camera movement, rather than the more common approach of moving an optical element inside the lens.

Sony claims that the Super SteadyShot anti-shake system in the A330 provides a 2.5 to 3.5-stop reduction in the blurring produced by camera shake. Translating that into real-world shutter speeds, a two-stop improvement means that a shutter speed of 1/30 second would give you the same resistance to blur from camera shake that a speed of 1/120 would without anti-shake. A 3.5-stop improvement would mean you could shoot as slow as 1/11 second and get the same results (blur-wise) as when shooting at 1/120 second unaided. Even the lower end of the specified range of effectiveness means a pretty significant improvement in one's ability to hand-hold long exposures.

When Super SteadyShot is activated, the SteadyShot scale on the right side of the viewfinder display indicates the degree of stabilization. A downside to Sony's body-based SteadyShot approach is that while you can see the results of stabilization on competing lens-based designs, you have only this scale to tell you how the A330's SteadyShot mechanism is doing. The upside, though, is that the SteadyShot scale does give you a very good idea of how hard the SteadyShot mechanism is working, so you can choose a moment when the camera is moving less to snap the shutter, thus maximizing your chances for a sharp image.

Sony A330 Anti-Dust Technology

To help combat dust particles on the CCD from changing lenses, Sony included both an anti-static coating on the CCD filter and anti-dust vibrations to automatically shake the CCD with the anti-shake mechanism each time the camera is shut off. There is also a manual cleaning mode, where the camera lifts the mirror and opens the shutter, allowing access to the sensor for use with a blower or other cleaning device.

Sony A330 Optical Test Results

Below are the results of our optical tests on the Sony A330. We used the 18-55mm kit lens as the benchmark, since most people will buy and use the camera in this configuration.

The images above were taken from our standardized test shots. For a collection of more pictorial photos, see our Sony Alpha DSLR-A330 Photo Gallery .