Just like the rest of the digital camera market, the digital SLR market itself is divided into several different categories. At one end you have the entry-level consumer DSLRs such as the Canon EOS 1000D (£400), Pentax K-m (£380) or Sony Alpha A200 (£270), while at the other end you have a small number of serious top-end professional cameras, such as the Canon EOS-1DS MkIII (£4900) and the Nikon D3x (£4800, review coming soon). In between these extremes there is a range of models aimed at photographers of intermediate skill, ambition and wealth. Most "semi-pro" photographers will choose a high-end APS-C camera such as the Canon EOS 50D (£790), Nikon D90 (£675), Sony A700 (£650) or Pentax K20D (£575), but for those wanting even higher quality there is another option; a compact full-frame DSLR.
Offering the same image quality and lens compatibility advantages as the D3x or EOS-1DS but in a smaller body and at a much lower weight, these are still serious cameras and are aimed primarily at professional photographers, however for the more affluent enthusiast they are a tempting proposition. Until quite recently the compact full-frame market consisted of just one model, the popular and long-serving Canon EOS 5D, launched before I started working for TR and only recently discontinued. However there are now a couple of other choices available. Canon has its EOS 5D MkII (£2100), Nikon has the D700 (£1750), but perhaps the most interesting is today's review camera, the Sony Alpha A900, launched in September last year and currently selling for around £1500 body-only. I'm not sure that a grand and a half for a camera can ever be considered good value, but it costs significantly less that its main rivals.
Although by type it is called a compact full-frame camera, there nothing particularly small about the Sony A900. The body measures 156.3 x 116.9 x 81.9mm, slightly larger than the EOS 5D MkII in all dimensions, and at a hefty 850g minus battery, memory cards or lens it's approximately 40g heavier than the Canon too. It's also quite a bit larger than the D700, although the environmentally-sealed Nikon is considerably heavier at 995g. The weight reflects the camera's robust build quality, because the A900 is designed for hard-working professional use, with a three-part magnesium alloy body over a high tensile aluminium chassis. The mirror box is carbon fibre reinforced polycarbonate resin, and the shutter mechanism is designed to last for at least 100,000 use cycles. The hatches and controls are sealed against dust and moisture, but it lacks the claimed splash resistance of some competing models.