On the surface, the Pentax K20D is not unlike the K10D. Under the skin, though, it's very different.

The biggest change is the swap to a 14.6-megapixel CMOS sensor. It's clear by now that you don't get a lot more definition with these higher pixel counts, but every little helps and it does mean that fine detail is resolved with a little more subtlety.

A sophisticated SLR

High pixel counts are often associated with higher noise, but this doesn't appear to trouble Pentax because the K20D goes right up to a maximum ISO of 6400.

It should be ideal for fans of low-light photography, then, and all the more so with Pentax's improved Shake Reduction (SR) system, which claims it can shoot at shutter speeds four stops slower before risking camera shake.

This system moves the sensor to counter camera movement, where Canon and Nikon systems put the stabilisation mechanism in the lenses. The advantage of the Pentax system is that it can be used with any current lens.

It's sophisticated, too - the sensor is moved with magnets rather than motors, and in three dimensions rather than two. The camera even uses focal length data from the lens to fine-tune its reactions.

Nifty dust removal function

Other noteworthy features include a basic Live View mode, pixel mapping (to identify and blot out any dead pixels), a dynamic range enlargement feature to cut down on blown highlights and a Dust Alert function to check for sensor dust.

This works very well. To activate the function, just point the camera at a white surface and press the shutter release. The camera then displays a white field with any dust spots clearly delineated.

If you find any (we did) you can activate the camera's dust removal process (we did) and then check to see if the dust has gone (it had). It's a simple and obvious system that works well.

The resolution and the advanced features make this camera ideal for keen enthusiasts looking to step up from a simpler, 'starter' SLR. Indeed, the K20D is part of an expandable, professionally-orientated system.

There's an optional battery grip and the ability to swap focusing screens to better suit particular styles and types of photography.

Hefty camera

This is all very impressive, but the K20D is far from perfect in real-world use. It inherits the solid, hefty construction of the K10D, but also some of its somewhat irritating minor controls.

One of these is the 'Fn' button on the back, which is used to access the drive mode, ISO, white balance and flash mode. On a camera of this type, these really ought to have their own buttons on the body.

Experienced photographers don't want to have to fiddle around with on-screen interfaces between shots. The other is the light and tacky-feeling navipad, which also manages to have a rather vague and indecisive action.

It's amazing how a detail as small as this can undermine your opinion of the camera as a whole.

The menus stick to the old Pentax style, too - they do look basic and dated compared to the interfaces on rival cameras. This is a serious, powerful photographic tool, but the menus look as if they belong to a simple snapper.

Poor Lens

And then there's the 18-55mm kit lens. It has its good points - a focusing ring with a distance scale, a metal mount - but its performance is pretty weak, particularly at the edges of the frame, where the sharpness falls away and quite high levels of chromatic aberration begin to appear.

These details are disappointing because, basically, this is a really good camera.

The viewfinder is big, there are two control wheels not one (ideal when you're adjusting shutter speed and aperture independently) and the larger-than-average body means that you can really get a proper grip on it.

Not only that, and notwithstanding the indifferent kit lens, the image quality is really good.

Live View mode

It's worth taking a closer look at the Live View mode, too, even though it's not as sophisticated as others. No, you can't change or even view the exposure settings, but it's easy to activate and it can help you frame shots in awkward positions.

In fact, though, it's only one of three Preview options, which can be selected via the Setup menu. The extra position on the power switch which activates the Live View can also be set to produce a 'digital preview', or a traditional depth of field preview in the viewfinder.

Strong pictures

It's a mistake to imagine image quality is all about pixel-by-pixel resolution or even lens performance. There are much broader tonal and colour differences between brands that defy proper measurement but which are apparent nonetheless.

Nikon cameras produce images with a different 'character' to Canon cameras, for example, and the K20D (like previous Pentaxes) has a character all its own, too.

It really does come quite close to the 'look' of a traditional transparency film. Not the oversaturated colours of Velvia, maybe, but Kodachrome 64, perhaps, or E6 slide films in general.

What this means to photographers raised on digital rather than film is that the Pentax's images show strong, natural-looking colours, dense but well-separated darker tones and good midtone contrast.

Keep detail in your photos

It has another trick up its sleeve, too - its expanded dynamic range option.

This can be applied when changing the ISO. It restricts the ISO range to 200-3200, but it doubles the dynamic range of the images captured.

This means that you can shoot on an overcast day and still keep sky detail without having to deliberately underexpose. Or shoot a reflective white subject like a vase without having to switch to RAW and fiddle about on the computer to recover those brilliant, subtle highlights.

We've seen 'highlight' modes before, but this one really works. This is one of the factors that helps give the K20D's images that 'film-like' look.

Excellent image quality

You might get sharper detail from a Nikon D300 (for example), and there are plenty of DSLRs with better kit lenses than this one. But the K20D's image quality, judged overall ('holistically', shall we say?) is excellent.

Commercial photographers might not be impressed, but those keen on subtler pictorial qualities will be excited.

The K20D is a great camera packed with great technologies that really work. The only thing keeping it from a higher score are its controls and interface design. If the K20D's innards were in an EOS 40D body, it would be irresistible.

Via PhotoRadar