Lens choice

On the subject of autofocus, the K-m can't match the smooth, near-silent systems used by Nikon and Canon. It feels noisy and coarse by comparison, though it does the job well enough. You'd have to invest in one of Pentax's more expensive zooms to get round this (the 17-70mm f/4, for example), but this will double the price.

It's worth considering, though, and not just with the K-m but the other Pentax models too. The standard 18-55mm lens is pretty poor, and with the K-m Pentax has released an even cheaper version with a plastic mount and no distance scale on the focussing ring.

Performance is okay in the centre of the frame, but detail softens considerably towards the edges and some pretty strong chromatic aberration creeps in. Only Sony's 18-70mm kit lens is worse than this. Canon's 18-55mm is marginally better and Nikon's 18-55 is better still.

Practical power

There's one more interesting thing about the K-m – it runs on four AA batteries. Long-time digital camera users will be wary of any camera that uses AAs because it's a pretty unreliable power source. NiMH rechargeables steadily lose charge even when they're not being used, and alkalines are both short-lived and unpredictable. But here it's different.

Pentax quotes an astonishing battery life of 1,650 shots if you use disposable lithium AAs. They're more expensive than alkalines, but with that kind of life expectancy it's a lot easier to swallow. A set of alkalines should last pretty well too, though there are no figures on this and it will vary from brand to brand. Don't expect more that 100-200 shots, though.

The Pentax K-m really does deserve to sell well. The kit lens isn't particularly good, but it's not alone there. The camera itself is excellent, and not just for beginners. It's well-made, robust, versatile and practical. Pentax never seems to rush into new markets, but when it does make a move, you can tell a lot of thought has gone into it.