Sony A55 Performance

A mixed bag when it comes to performance, ranging from below average to exceptionally fast.

Startup and shutdown times are slower than average for an SLR. Shutdown is slow probably due to sensor cleaning. Buffer clearing times are quite slow, but not surprising considering the deep buffers and large files.

Mode switching times are about average for an SLR.

Looking at the Sony A55V's ability to determine that it's properly focused when shooting the same target multiple times, its speed is about average for a consumer SLR. The SLT-A55V required 0.22 second for full AF using the center focus point. This decreased slightly to 0.218 second in wide-area AF mode. Enabling the flash raised the lag to 0475 second, to account for the flash exposure preflashes. Continuous autofocus mode lag time was 0.215 second and manual focus was only slightly faster at about 0.214 second. When prefocused, shutter lag was 0.103 second which is good but a bit slower than average for an SLR these days, and somewhat of a surprise for a camera that doesn't need to wait for a mirror to be raised before taking the shot. Keep in mind that the shutter is normally open though, so it needs to be closed and re-opened to take the exposure.

To minimize the effect of different lens' focusing speed, we test AF-active shutter lag with the lens already set to the correct focal distance. We also use the same Sigma 70mm f/2.8 macro with every camera (on all platforms except Four Thirds/Micro Four Thirds and Nikon consumer models lacking an in-body focus motor), to further reduce variation, and because our tests showed that focus-determination time with this lens was close to the fastest, across multiple camera bodies from different manufacturers. Being an older design with a non-ultrasonic motor, it wouldn't be the fastest at slewing from one focus setting to another, but that's exactly the reason we measure focus determination speed, which is primarily a function of the camera body, vs focus adjustment speed, which is primarily a function of the lens.

Shot-to-shot cycle times were about average for an SLR, at about 0.5 second per frame for any quality. Continuous mode speeds were excellent though, especially for a non-pro SLR, at about 6 frames-per-second for large/fine JPEGs in Continuous Hi mode. Speed Priority mode is exceptionally fast for any SLR at 9 frames-per-second for large/fine JPEGs and 10.2 frames-per-second for RAW or RAW + JPEG. If we ignore a consistent hiccup we encountered at the 16th frame in large/fine JPEG mode, it too achieved 10 frames-per-second. Remarkable.

Buffer depths are very good for a consumer model, at 39 frames for large/fine JPEG frames with a fast SDHC card. We didn't test with a Memory Stick. Buffer depths are generally a bit lower in Speed Priority mode, at 32 large/fine JPEGs, 19 RAW and 18 RAW + JPEG frames, but still very good. The flash takes 3.7 seconds to recharge after a full-power shot, which is good.

Connected to a computer or printer with USB 2.0, download speeds are very fast; definitely fast enough that you will likely not feel the need for a card reader.

Bottom line, the Sony Alpha SLT-A55V's performance ranges from below average (startup and shutdown), to average (mode switching, autofocus, single-shot cycle times), to much better than average (burst speed and buffer depth). Its super fast burst speed should come in very handy for sports and active kids.

Battery
Below average battery life compared to a traditional SLR with optical viewfinder, but decent battery life for an interchangeable lens camera with EVF.

The Sony A55 uses a custom rechargeable lithium-ion battery for power, and ships with a charger. Battery life is a below average compared to an SLR using an optical viewfinder, but just about average compared to an SLD with electronic viewfinder. We recommend you pick up a spare battery and keep it freshly charged and on-hand for extended outings or shooting video.

The table above shows the number of shots the camera is capable of (on either a fresh set of disposable batteries or a fully-charged rechargeable battery as appropriate), based on CIPA battery-life and/or manufacturer standard test conditions.

(Interested readers can find an English translation of the CIPA DC-002 standards document here. (180K PDF document))

Storage
The Sony A55 accepts SD (including SDHC and SDXC types) or Memory Stick Pro Duo memory cards. No card is included with the camera.

We strongly recommend buying either a large capacity SDHC, or a large capacity Memory Stick Pro Duo card, at least a 2GB card, preferably a 4-8GB one, to give yourself extra space for extended outings and while shooting video. (Check the shopping link above, cards are really cheap these days, so no reason to skimp.)