Ever since Canon introduced the EOS-300D in 2003, the lower end of the SLR market has been one of the most profitable camera sectors. Canon and Nikon continue to dominate the market, making Sony rather late to the party. The impetus behind the A100 came from their acquisition of Konica Minolta's camera business, which gave Sony the imaging prowess to compete with the other big names and release this, its first SLR.
But enough market background, what is the Alpha 100 like? Good, but not perfect, is the short answer. First, the good news. Although the Alpha's body is very similar to the old Konica Minolta Dynax 5D, the CCD and controls are new. So £650 buys you a mighty 10-megapixel CCD and a versatile 18-70mm kit lens that compares well to the shorter 18-55m lens you get on the Nikon D50.
As with the old Dynax, the CCD incorporates anti-shake technology - Super Steady Shot, in Sony speak - which combats judder at the far end of the zoom and generally helps to keep shots in focus. It works really well, and it's great to see that Konica Minolta's pioneering work in this area did not go to waste.
Another welcome innovation is the Bionz image-processing chip, which claims to maximise dynamic range in order to preserve detail in highlights and shadows. Certainly, this is good to have, but we were hard-pressed to notice a massive difference on our test shots. It's a useful addition if you regularly do large prints, however, where fine detail is more important.
Another useful widget is the anti-dust device, basically a glass cover for the sensor that's been coated with indium tin oxide to help keep dust motes off. The CCD also vibrates at high speed every time the camera is turned on, a feature that will reassure photographers who worry about dust getting into the SLR body every time they change lenses.
The price you pay
In use, we found the Alpha fast and responsive, although the loud shutter is a nuisance for candid shots. The camera feels rather cheaply made too. It's a bit remiss of Sony when you consider that sturdy, attractive rivals such as the Nikon D50 can now be picked up for £250 less.
On a brighter note, the kit lens is of high quality, and being able to zoom to 70mm is a distinct advantage. The lens mount will take Konica Minolta lenses and, in fact, any Minolta lens from the last two decades, but just to confuse matters, Sony is also planning a range of new Zeiss lenses for the Alpha. Obviously, your collection of Nikon, Canon, Pentax or Olympus SLR lenses won't work at all.
Image quality is generally good and, while you do notice some purple fringing from the lens, it's a lot better than the older Sony power compacts. The metering is particularly adept, and it's easy to adjust exposure settings to cope with challenging light.
ISO (light sensitivity) goes all the way up to ISO 1600, and noise, or unwanted digital grain, is well controlled, although it's more noticeable on indoor shots. As is standard on budget SLRs these days, you can shoot in JPEG or RAW.
Image detail is right on the money, which is only to be expected from a 10-megapixel sensor. All those extra pixels are probably overkill unless you do A3 prints, but again, they are nice to have, as is the ability to save shots on CompactFlash cards. There's an adaptor for Sony's irritating MemoryStick Duo format, which it's backing to the bitter end, but most people will go for the cheaper, more convenient CF option.
For the money, you get a good range of manual controls with the camera, although this is not aimed at the semi-professional. Tweaking aperture and shutter speed on the LCD is easy enough, with nice clear menus. The built-in flash is OK too, but the proprietary flash hotshoe means that you will only be able to use Sony or Konica Minolta external flash units.
So will the Alpha mark a new dawn for Sony in the budget SLR market? The problem is, at £650 this camera is steeply priced compared to its rivals. Unless you're a sworn Sony or Konica Minolta loyalist, we'd hold off until the price comes down. Geoff Harris