Sony's first digital SLR looks like one of the most exciting and innovative newcomers to arrive on the scene for some time. With ten-million pixels, built-in anti-shake and 20 new lenses on the way, Sony has hit the ground running.

Behind the scenes, though, there's another story which puts everything into context. In July 2005, Konica Minolta and Sony made an announcement that they would be jointly developing a digital SLR system. That might have raised a few eyebrows, given that both companies were rivals in the digital camera market, but it wouldn't be the first time such a partnership had been forged.

But then in January 2006 Konica Minolta made the shock announcement that it was withdrawing from the digital camera market altogether and that Sony would take over its SLR business. At the time, Konica Minolta was making the likeable and rather interesting 6Mp Dynax 5D digital SLR, and it was disappointing to think it might disappear.

Well it hasn't, not exactly. Let's put it this way. The A100 is exactly what you might get if you decided to take a Dynax 5D and put in a higher-resolution sensor, upgrade the image processing and apply a cosmetic makeover. No doubt there's a lot more that's gone on inside that we don't know about, but the end result looks and feels very much like the old Konica Minolta Dynax 5D.

There's a good side and a bad side to this. The body is compact, sturdy and - small though it is - not quite as cramped as Canon's EOS 350D. Yes, it's plastic, but the finish is good, the camera feels solid and robust and the controls are nice - the minor controls, especially, have a better finish than those on the Dynax. There have also been some changes to the control layout, which we'll come to shortly. The 2.5-inch LCD on the back has enough pixels (230,000) to produce a really sharp, bright display, both during image playback and when making adjustments to the camera settings while shooting.

Shaken not stirred

On the bad side, the A100's startup and shutdown times are a fraction slower than those of its rivals, and accompanied by the same bizarre internal clanking and shunting that was such a feature of the Dynax 5D.

We won't stress the similarities of these two cameras any more since few users would have encountered a Dynax 5D anyway, and we'll be approaching the A100's design from a completely fresh perspective.

We imagine that all the mechanical noise is connected with the A100's CCD-shifting, antishake system (Pentax employs something similar in its new K100D digital SLR reviewed on p52). This aims to offset the effects of camera shake at slower shutter speeds by detecting and measuring movement and then compensating with opposite movements of the sensor. It's claimed this enables you to use a shutter speed up to 3.5x slower than usual without incurring camera shake.

Other manufacturers, notably Nikon and Canon, offer image stabilisation systems which are built into specific lenses rather than the camera body. Canon's image stabilized ('IS') and Nikon's vibration reduction ('VR') lenses are expensive, whereas the Alpha's system potentially extends the advantages of image stabilisation to any lens. It works well, too, as long as you remember that it improves your odds of getting a sharp shot without actually offering any guarantees.

The other thing with image stabilisation systems, of course, is that they can counter camera movement but not moving subjects. Sometimes higher ISOs are the only answer.