Sony Alpha A550

Speed and Timing

Using the Speed Priority Continuous Advance mode, shooting large Fine JPEGs, we zipped through 6.67 shots per second, a blistering pace for a mid-priced SLR, and particularly impressive given the high 14.2-megapixel resolution.

The A550 supports three continuous shooting speeds. The Lo setting promises a maximum 3 images per second whether you’re shooting with the viewfinder or in Live View mode. The Hi setting claims a maximum 4 images per second when shooting Live View, and 5 when using the viewfinder. There is an even faster shooting mode available, though, if you select Speed Priority Continuous Advance. This mode can get up to 7 shots per second, but exposure and focus are set at the first shot. We consider that a reasonable approach for many shooting situations, and used this mode in our speed and timing testing.

The A550 will shoot up to 32 images continuously before slowing down when to set Fine image quality, and 116 images in the Standard setting. For RAW files without JPEGs, the limit is 14.

Focus Speed

The A550 uses a 9-point autofocus system when shooting with the viewfinder, with eight line sensors and a cross-hair sensor in the middle. There are two focus modes, Single-shot and Continuous, plus an automatic mode that lets the camera make the call.

By default, the camera uses an Eye-Start AF system when shooting with the optical viewfinder. Holding the camera up to your eye automatically starts the autofocus system, which then continues to adjust focus as you move the camera. If you’re used to holding the shutter button halfway to autofocus, this alternative approach takes some getting used to. It can potentially shave a second or so off your ready-to-shoot time. At the same time, having the camera start autofocusing on its own threw off our tried-and-true shooting rhythm, and we found that as we held the camera between shots, we frequently triggered the autofocus as the viewfinder moved close to our body. Full credit to Sony for providing the option, but we went into the Custom menu and turned it off.

In well-lit settings, the autofocus speed was very good, but moving into low-light situations we ran into trouble. First problem: the system uses the flash as an autofocus assist instead of a dedicated AF assist lamp, blasting two blinding staccato bursts of light — so much for candid shots in a dark room. Second problem: even with the autofocus assist, the camera failed to achieve a proper focus too often in night shooting situations.

There are three focus area options: Wide, Spot, and Local.

The local focus area option is unnecessarily tricky to use because of the poor viewfinder display as you select a focus point. It blinks briefly while you hold the directional pad down, but that’s hard to see, and there’s no indication afterward to show which of the nine points you’ve selected until you see the point blink red to confirm focus. Also challenging is moving the pad diagonally to select the corner points. All in all, it’s a clumsy system.

The manual focus system, on the other hand, is nicely designed. The in-focus sensor in the viewfinder display blinks as you get near a sharp focus and then lights steady when you achieve it. In addition, there’s a dedicated button on top of the camera for the Manual Focus Live View Check function. Pressing it raises the mirror and temporarily shows the image on the Live View screen for focusing purposes. You can enlarge the image in two steps, 7x and 10x, and choose whether or not to have a nine-block grid overlaid on the display. Press the shutter and the camera immediately takes the shot, and returns to viewfinder mode. It’s easy to use, and very useful, especially when you’re shooting with the camera mounted on a tripod.