Sony Alpha A100

As Sony's first entry into the digital SLR space, the 10.2 megapixel Alpha A100 has a lot of expectations to live up to. While it is a nicely constructed entry level unit that performed well in a number of our imaging tests, it is let down considerably by the default lens, which generated high levels of chromatic aberration. We also noticed quite a cool tone to a lot of our shots, even after adjusting the white balance appropriately.

One of the best elements of this model is the design. The A100 is weighted perfectly and sits very nicely in the hands, while the thick, rubberised grip is comfortable and most of the controls are easily accessed. We had mixed feeling about the control layout. Sony has combined all the major imaging options onto a single dial located on the top left hand corner of the unit. This quite unconventional approach leaves the camera's back a little sparse, and makes for a rather simplistic interface. This is great for new users, but may leave experienced photographers missing a more traditional setup. We also had an issue with both this dial, and the main function wheel; they are very stiffly mounted. On most other SLRs the wheels can be manipulated with a single finger, but on the A100 you have to adjust your whole grip to change things, which can rapidly become a pain. This issue aside, all the controls are well labelled and intuitive to use, so most novices should easily master the interface in a matter of hours.

In our image quality tests the A100's results were similarly mixed. Imatest awarded it a score of 1771 for sharpness, which is a great result and more than satisfied our expectations of the new crop of 10.2 megapixel sensors. Our shots exhibited almost no visible fringing and were extremely sharp for the most part.

However its score of .162% for chromatic aberration was far less impressive. For any camera this is a very poor result, and for an SLR it is even more so. It was clearly visible as a red and purple halo ringing certain objects towards the exterior of our shots. We originally put it down to a fault in the camera, but further testing with multiple lenses revealed the default lens was the culprit. The A100 ships with an 18-70mm lens by default, and an 18-200mm lens if you buy the dual lens kit. When testing with the extended lens the problem was much less pronounced, although still visible to some degree. It is a real shame Sony didn't bundle better quality glass with the A100 as it is a big limiting factor.

Its performance in other areas, while marginally better, was not as impressive as its sharpness result. Scoring 9.97 in Imatest's colour test, it wasn't quite as impressive as some other SLRs we've looked at recently such as Olympus' E-330. We can largely attribute this result to the camera's colour balance, which was visibly skewed in most of our shots. Comparing identical pictures with other SLRs in our offices revealed that the A100's pictures all had quite a cool tone to them. It was most noticeable in patches of white but affected all the other shades. Even using manual white balance or adjusting to the appropriate preset didn't fix this, and it was a big disappointment.

The A100's noise performance was quite solid, but again not particularly impressive. At ISO 100 it scored .47% in Imatest, which is slightly ahead of some of the best compacts we've seen recently, but doesn't compare with many SLRs that score .37% or less. At this level noise was very slightly visible at big magnifications, but it was extremely fine and won't be an issue unless you expand your shots to poster sizes. As we increased the sensitivity though, it began to become more prominent. At ISO 400 the noise, while still fine and white, was quite evident and created a noticeable degradation in sharpness. At ISO 800 and ISO 1600 it began to become visible as chroma noise (colourful blotches) and we wouldn't recommend using the A100 at these levels.

From one type of noise to another, our audible noise tests also revealed another issue with the A100; the motor is quite noisy and a little slow. When compared to competing units from Canon and Olympus it took slightly longer to adjust focus and was noticeably louder when doing so. This paralleled the shutter and mirror movement, which was also a little louder than normal. This isn't a big issue, but is noteworthy nonetheless.

With regards to features, the A100 is a fairly standard entry level SLR. It offers ISO sensitivities up to 1600, manual, custom and preset white balance modes, six scene modes and a number of auto focus types including spot and wide. The continuous shot mode is quite reasonable, taking 3.3 shots per second, and is backed up by both exposure and white balance bracketing. There is also Sony's new anti-shake technology, which we are pleased to say operated excellently. It is great that more and more SLRs are coming packaged with this type of technology, as it makes a big difference when shooting free-hand at high zoom levels. Sony's implementation on the A100 is about on par with Panasonic's efforts over the last year, and really helps keep shots crisp and blur free.

Sony has implemented a few other new features on the A100 as well, most notably dust reduction technology. Prior to this release, only Olympus had really successfully tackled dust reduction in SLRs and while Sony's effort isn't quite as good, it is still very effective. It works by shaking the sensor after you power down the unit, and goes a long way to rectifying dust problems, which are often a big issue for SLR users who regularly change lenses.

The other new feature is Sony's dynamic range optimization, which theoretically helps balance shots that are over or under exposed. Our testing revealed that while it did make a very marginal difference it isn't really noticeable unless you do a side by side comparison. The only situation where it proved to be a little more useful was in shots with high levels of backlighting.

Overall the A100 is a competent but not outstanding unit. It sports a very nice design and its pictures are quite sharp, but the colour balance is a little off and there are extremely high levels of chromatic aberration with the default lens.