Pentax claims that the *ist DS is the smallest and lightest digital SLR on the market at moment. This isn't just some hollow boast based on a few millimetres shaved here and there, but a difference that's obvious the moment you see it and pick it up. It makes the Canon EOS 300D seem bulbous, and the Nikon D70 look like a great battleship of a thing.

Size isn't everything, of course, and many a good camera has been ruined by being too small to hold comfortably. The *ist DS manages to steer clear of this trap, and although its lack of height in the body means that your little finger overhangs the base of the camera, it still offers a comfortable and secure one-handed grip.

This isn't the first Pentax digital SLR - the original *ist D came out well over a year ago (reviewed in DCM November 2003, it scored 94%). Although the *ist D is undoubtedly an excellent camera in its own right, it's fairly expensive compared with its rivals. Selling at a street price of around £740 with lens, the *ist DS is a pared-down version of its older brother. And, at this price, it now compares much more favourably with the latest discount prices on the ageing Canon EOS 300D, and it undercuts the D70, even with Nikon's latest price realignments.

These reductions in size and cost lead us to ask: has Pentax taken away too many features of the original *ist D and left us with a camera that's not up to the job? And does the low price point mean compromises in build quality too?

The *ist DS is designed for all levels of photographer, including first-time digital SLR users. It has a simplified feature set and control layout, and externally it's remarkably free of knobs and buttons (the downside of this means that many common functions are less accessible).

On the back of the camera a Fn button displays a four-way menu system on an LCD. You press up on the navipad to change the drive mode, right to alter the ISO, down to change the flash mode and left to alter the white balance.

There's also a choice of three different metering patterns (multi-pattern, centre-weighted and spot), but you have to trawl through the menus to get to them. Although you can get by using fill flash and a little experimentation, you may be disappointed to note that the flash modes don't include any slow sync options.

Overall, however, the *ist DS does in fact do pretty well everything you need in a budget digital SLR.

Despite being a budget camera, the *ist DS is built around a rigid stainless steel chassis, and there's a feeling of solidity and precision about it. Its only weakness is the lightweight feel to the navipad and central OK button, but otherwise this camera comfortably beats the 300D for 'feel'.

Power comes from four AA cells or two lithium-ion rechargeable batteries. If you use AAs, you're likely to stick to rechargeable NiMH cells. These aren't as reliable in use or storage as lithium-ion cells, but in the *ist DS they offer a capacity of up to 440 shots (more if you don't use flash), which isn't bad at all. Disposable CR-V3 cells are expensive, but they're an even better option because they can last up to 850 shots.

This suggests that the camera has a pretty modest power consumption and hence less risk of unexpected power loss. It's also remarkable that Pentax is able to manufacture the world's smallest digital SLR, yet still find space inside for four AAs rather than the much slimmer lithium-ion cells that are used by other manufacturers.

In one respect at least, the *ist DS is superior to the original *ist D. The only 'kit' lens option with the older camera is a flimsy and lacklustre 18-35mm zoom. In contrast, the *ist DS can be bought with a digital lens that has a better build and wider focal range. The 18-55mm zoom is an exact match for the 18-55mm lens supplied with the Canon EOS 300D, though neither can match the focal range of the Nikon D70's 18-70mm.

Like the Canon lens, the Pentax zoom has an aperture range of f3.5-5.6. It's in the handling, however, that the two lenses differ. First, the Pentax lens has a smoother and firmer zoom action. Second, the focusing ring at the front of the lens has a far better feel to it, and there's a distance scale too. In addition, the front element of the lens doesn't rotate during focusing, which means that you can attach polarising filters and graduates and not have to reposition them every time the camera chooses a new focus point.

The *ist DS has another, less obvious, advantage over Canon's EOS 300D: the viewfinder. According to Pentax, it's equal in size, clarity and brightness to film camera viewfinders. You might not notice the difference at first, but if you have the opportunity to put the Pentax to your eye, then the Canon and finally the Nikon, you'll find that the viewfinders in the Canon and Nikon do indeed seem rather cramped.

The larger viewfinder image isn't just cosmetic, either - it enables more precise focusing with wide-angle zoom settings. And, amazingly in an amateur camera, the focusing screens are interchangeable, so you can substitute a split image or 'scale matte' screen.

There are a couple of other surprises. One is a sensitivity range that goes from ISO 200 up to ISO 1600. The other is the camera's compatibility with a huge number of older Pentax lenses, right back to the 1960s and screw-mount Takumar optics that can still be used on this camera, via an adaptor. There are some operational restrictions (metering and exposure modes), depending on the type of lens, but the fact that you can use them at all will be a welcome surprise for longstanding Pentax owners.

Although the *ist DS uses SD memory cards rather than CompactFlash, it isn't the problem that it might have been because these days SD cards are readily available in high capacities and at comparable prices.

The Pentax's image quality is every bit as good as its rivals. Colours and contrast are exceptionally strong, there's little colour fringing and the lens shows low levels of barrel distortion.

So, if you're looking for a compact and satisfying build, plus image quality as good as a 6-megapixel sensor can provide, then the *ist DS is surely the new budget standard. You certainly won't be disappointed...