Sony DSLR-A100 Performance

Sony Alpha A100 Timing
Good performance, very responsive.

Startup and Shutter Lag
The Alpha A100's performance is quite good overall, beginning with a quick startup time of 1.1 seconds. Shutter response is quite good as well, at 0.31 second with the kit lens at full wide angle. "Prefocusing" the camera by half-pressing and holding down the shutter button before the final exposure also results in a good time, at 0.116 second. We were a little surprised though, to see the shutter lag in manual focus mode as long as 0.3 second: We'd have expected it to be closer to the prefocused time.

Shot to Shot Cycle Times
Shot to shot cycle times are very good, at about 0.58 second per frame for up to 21 large/fine JPEGs in succession, and RAW mode is also quite good at 0.65 second for eight consecutive frames. (Sony claims unlimited sequence lengths for large/fine JPEGs, but we found that a standard noise target with extreme high-frequency content reduced the buffer capacity to as little as 14 frames, even with very fast memory cards. On more typical subjects, you should easily be able to get 20+ shots in a series before having to wait for the memory card to catch up.)

Continuous Mode Performance
The A100 performs well in Continuous-mode, capturing about 2.85 frames/second, for up to eight full resolution shots in succession. (Even in RAW+JPEG mode, the Continuous rate is the same, though only for three consecutive frames.) The flash takes about five seconds to recharge after a full-power shot, about average for a DSLR.

Download Speed
Download speeds are impressively fast, meaning you won't need a separate card reader to speed things along. While not as fast as some higher-end DSLRs we've tested, the Sony A100 is more than capable of handling most action shots, and should do a great job of capturing pictures of wiggly children. Bottom line, the A100 is well-suited for a wide range of photographic needs.

Battery
Good battery life.

The Sony DSLR-A100 uses a custom rechargeable LiIon battery for power. The table above shows maximum number of shots based on the CIPA battery-life standard. The rated 750 shots per charge is quite good, about typical for a consumer DSLR. Do keep in mind though, that time spent viewing images on the camera's LCD screen uses up battery power. If you plan extended outings, we still recommend purchasing a second battery along with the camera.

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

Storage
As is usually the case with DSLRs, no card is included with the Sony Alpha A100, although it accepts CompactFlash cards.

The Sony A100 uses CompactFlash Type I or Type II memory cards, the Hitachi Microdrive, or Memory Stick Duo cards (via the included CF adapter) for image storage. The camera ships without a memory card, so you'll want to purchase one at the same time. The CompactFlash slot is on the right side of the camera, covered by a hinged plastic door that slides opens easily and snaps shut crisply. The card inserts with the connector edge going in first, and the rear of the card facing the back of the camera. A small button beside the slot ejects the card by popping it up slightly, letting you pull the card the rest of the way out.

Although individual CompactFlash cards cannot be write-protected or locked against erasure or manipulation, the A100 lets you lock individual images or groups of images through the Playback menu. Once protected, images cannot be erased or manipulated in any way, except through card formatting. The Playback menu also lets you delete images shown in the LCD display, change the number of images in the Index display, create a custom slide show, and set images up for printing on DPOF compliant printers.

Three image resolution settings are available: 3,872 x 2,592 pixels (Large); 2,896 x 1,936 (Medium); and 1,920 x 1,280 (Small). Files may be saved in Fine or Standard JPEG compression levels, as well as a compact RAW format. (By its nature, the RAW format only saves the full-resolution image size.) The A100 also allows you to simultaneously save images in both RAW and JPEG formats, allowing you to have the convenience of JPEG files but the security of a RAW copy of your images should you desire the maximum quality later.

The table below summarizes the compression ratios and number of images that can be stored on a 256MB memory card (a common size that should probably be considered a minimum for use with the camera), with each Resolution / Quality (JPEG Compression) combination.

We strongly recommend buying at least a 256MB card, preferably a 512MB or 1GB one, given the large file sizes, to give yourself extra space for extended outings.