HandlingThe Pentax RZ18 isn't the most stylish compact camera we've seen this year. In fact, the rather unflattering build and finish serve as a reminder that Pentax is out to keep the cost of this camera down to a minimum. The camera has a thin matte black plastic casing, and even though its textured surface feels quite nice to handle, the buttons aren't particularly pleasant to use. It would have been nice to see some kind of handle to improve grip too, or at least a rubber strip instead of the flat indent that's supposed to serve as a thumb-rest.
On the upside, the controls don't wobble or feel loose and they aren't stiff or hard to press, even if the four-way pad flexes when you press on it. All in all, the camera has been built and assembled with care. We liked the textured finish of the black RZ18 we were sent to test and, in the absence of a handle (see above), it helped us keep firm hold of the camera. The interface is nice and simple and although the menus aren't very stylish, they're clear and easy to read.
The screen definition of 460,000 dots is pretty standard for a mid-range compact, but the TN screen panel is a bit of a let-down. This type of screen has tight viewing angles, and so the LCD looks black when viewed from below. Don't rely on the screen for sorting and deleting photos either, as the weak gamma means that light greys will look white onscreen. Similarly, although the colour temperature is excellent, colours aren't reproduced with any kind of accuracy on the RZ18 screen.
The RZ18 is a camera that's easy to use, but the menus are a bit rough and ready. The overall design (complete with pixelated typeface!) is pretty basic and abbreviations aren't always as clear as they could be.
ResponsivenessThe autofocus is reasonably speedy, working in under half a second in good light and under a second in low light. It's not always that consistent, however. For example, in low light, the camera sometimes focuses at 7/10 ths of a second, but sometimes dithers for over a second and a half and occasionally refuses to focus at all. At telephoto settings, focusing can be a bit hit and miss too—you're best bet is to force the AF to lock on by half-pressing the shutter-release button and making sure the shot's in focus before you take a picture.
Bearing in mind that the RZ18 has an 18x zoom lens, the start-up time of 2.2 seconds is about average. The photo-to-photo turnaround of 2.7 seconds is a bit disappointing though, and the 0.7 fps continuous shooting mode is pretty slow too.
Picture QualityThe Pentax RZ18 lens has the same set of tech specs as the Nikon S9100, with an 18x zoom equivalent to 25-450 mm and aperture settings of f/3.5-5.9. However, unlike its Nikon counterpart, this camera doesn't have a BSI CMOS sensor, and instead comes with a classic 16-Megapixel CCD.
The RZ18 tends to take pictures that are quite dense (low exposure) to try and mask digital noise. Sensitivity is nothing to write home about, and while noise is controlled well (smoothing and granularity under control) up to 400 ISO, things go downhill at 800 ISO, as the camera tries to counteract granularity with smoothing that's so strong it's even visible on a 4" x 6" print (10 x 15 cm). The 6400 ISO setting is just plain ridiculous, as even a 2" x 3" (6 x 8 cm) print would look blurred!
The lens doesn't give consistent performances. At wide-angle settings, the frame isn't as sharp around the edges and a few coloured fringes can be seen in full-size shots. Don't get us wrong, it's still decent enough—while the Sony HX9V and Canon SX230 both do better, plenty of other camera lenses do a much worse job. However, quality degrades as you start to zoom. At around 200 mm, pictures aren't particularly sharp anywhere in the frame and the edges are just plain blurred! Things improve towards the maximum telephoto settings but, all in all, the lens isn't really a strong point for the RZ18.
The stabilisation system didn't prove particularly effective in our Barbie without flash test. The RZ18 has to push up to 800 ISO to take a picture that's reasonably sharp, and even then the shot doesn't look consistently clear until 1600 ISO. We also noticed that the camera struggled to set the white balance correctly under incandescent light.