Ricoh GXR review

As unusual designs in digital photography go, this one takes the prize for 2010 so far. The Ricoh GXR is not so much a camera with interchangeable lenses as a camera platform with interchangeable cameras.

The body itself contains no image sensor; only the LCD monitor and associated electronics, battery and SD card slot. To turn it into something that will take photos you need to attach one of the lens units. Each lens unit is a self-contained, sealed box incorporating not only a lens but also the iris mechanism, shutter and image sensor – essentially a complete camera.

That gives unique flexibility, but it does make the lens units enormously expensive. There are currently only two on offer: the first, the S10, sports the same type of small, optically stabilised 1/1.7in sensor you find in digital compacts, plus a 24-70mm zoom lens. Buying it separately from a GXR body will set you back around £255 exc VAT.

The second, the A12, features a high-quality fixed-focal-length 50mm f/2.5 lens, plus a large APS-C sensor. That means you’ll get digital SLR-level image quality, but you’ll pay £510 exc VAT for the privilege of buying one separately. Incidentally, the GXR body doesn’t have an optical viewfinder, only the 3in LCD display. If you want the optional LCD hot shoe-mounted viewfinder, it’ll set you back an outrageous £219 inc VAT.

Ricoh claims a couple of upsides to a sealed lens and sensor unit. First is the ability to precisely tailor the lens and sensor assembly, which theoretically allows a better design of low-pass optical filter to be used, reducing colour noise. Second is the fact that you’ll never need to worry about dust contamination from lens changes.

We can't argue with that, but there are weaknesses too. All lenses in the GXR system use contrast-detect autofocus and this is painfully slow compared to the phase-detect system used by a true DSLR. To combat the sluggishness, there’s a nice feature called full-press snap. With this activated, pressing the shutter button all the way without pausing at the halfway mark immediately takes a shot at a predefined, fixed focus point. However, there’s still a clearly perceptible shutter lag.

Quality of the A12 50mm macro lens and APS-C sensor combination is very high. The maximum image-size ratio is 1:2, which means the image projected onto the sensor is half actual size rather than the true 1:1 ratio strictly required to qualify as a true macro lens, but nonetheless you can get very close indeed. With the aperture set to f/2.5 the depth of field for macro shots is extremely shallow, giving you plenty of scope for creative close-up photography.

There was no hint of chromatic aberration in any of our test shots with the A12 lens, images were pin-sharp and noise was well controlled too, even up to the maximum ISO 3200 sensitivity. Ricoh’s claim to be able to control colour noise better with the combined lens and sensor unit seems well-founded. As with the GXR body, the whole lot is built around a sturdy magnesium-alloy shell and we’d have no concerns at all about longevity.

Results from the small-sensor S10 are less impressive. Noise is far too high to be useable over ISO 800, but again chromatic aberrations are well-controlled. The results essentially look like just like those from a compact camera, with the standard small-sensor problem of limited dynamic range tending to clip the highlights. When you bear in mind that this particular compact camera costs nearly £700, it’s not a great show.