Following in the footsteps of the Pentax K10D we looked at last year comes the new and improved K20D. Sporting the same impressive build quality as its predecessor, this unit is more of an upgrade than anything else. However, the additions are welcome. With new features such as live view and an improved 14.6-megapixel sensor, this model is a competitive entry in the overflowing mid-range SLR category.
This time around Pentax has gone with a CMOS sensor manufactured by Samsung — previously it used Sony CCDs. Theoretically, this change means increased light sensitivity and a better signal-to-noise ratio, as well as more pixels.
In all of our image quality tests the K20D performed well and stacked up nicely against competing models from Canon, Nikon, Sony and Olympus. In our sharpness and resolution tests we were extremely impressed with the camera's performance. This new sensor does an impressive job of capturing crisp shots and maintaining detail.
When we tested using the stock 18-55mm lens chromatic aberration was fairly well controlled. There was no visible purple fringing in outdoors shots and only slight haloing on high contrast edges. Sharpness was fairly uniform across our shots, with only minor corner softening evident.
Imatest found the K20D's colours to be extremely accurate. It revealed some slightly oversaturated reds and somewhat pale blues, but the overall colour reproduction was extremely pleasing. The automatic white balance setting exhibited a slightly warm cast, but it was nothing serious.
Image noise performance was fairly solid as well, although the K20D was perhaps a little behind the competition in this regard. ISO 100 to ISO 400 were fine, producing clean, smooth shots. At ISO 800 there was a slight haze of chroma noise evident. It won't be problematic even up to ISO 1600 unless you are making sizeable enlargements. Settings of ISO 3200 and beyond produce unacceptable noise levels.
Carrying over the 11-point autofocus system from its predecessor, this unit is one of the quickest performers on the market. We were constantly amazed by how quickly we were able to focus and capture a shot. It also performed well in most other speed tests, with an almost instantaneous start-up time and minimal time between shots. The burst mode is the only area of disappointment; while its three frames per second is still quite admirable, other units on the market go as high as 6.5fps.
The build quality is as impressive as it was on this unit's predecessor. While it is quite heavy, even for a camera in this class, it feels wonderful to hold and is solid as a rock. It also has the added bonus of being dust- and weather-proof. Pentax claims the K20D has 74 seals designed to secure the internal components and keep them from harm. That isn't to say the camera is 100 per cent guaranteed to survive any inclement conditions, but the extra durability is nice.
Dust reduction is included and is as effective as previously. We'd still give the edge to Olympus' system, but any included protection is a good. There is also a built in dust-detection system, which helps locate dust particles that happen to get stuck on the sensor.
Image stabilisation is built into the sensor — an increasingly popular trend for SLRs. Combine this with the fact that the K20D is compatible with any past Pentax lens and you have a huge variety of shooting options all of which are stabilised up to four stops.
Another feature common to newer SLRs is live view; it's not one Pentax has neglected. However, its implementation could use a little work. While you can use the LCD to frame shot,s you have to focus manually or use the clumsy mirror lift system (which has a few seconds' delay). This means that although it may work for inanimate shots, trying to capture a moving target using live view is going to be a fruitless endeavour. We were also annoyed that the aperture and shutter speed disappear from the top mounted LCD when live view is running, making it difficult to tweak your shots.
Both RAW and JPEG formats are supported (Pentax proprietary and Adobe standard RAW types are on offer).
