We test the K20D for image noise and general usefulness and find it to be an amazing camera.
We were lucky enough to have the Pentax K20D in for review when it was the last opportunity to get down to the beach house for the end of the warm season (in Australia).
The Pentax K20D is an impressive camera from the specifications: 14.6MP resolution, Live Preview and in camera shake reduction. It is even more impressive in your hand. Pentax have been looking much more competitive of late and the K20D really shows that. The ergonomics are excellent, it has a solid feel and an assurance that it will last a long time. Image quality is great at low ISO, as we will see and it has most of the features anyone would need.
But how does its images hold up as you increase ISO? The fact that it runs a high resolution compared to some other low to mid end cameras could indicate an inherent noise issue.
The following shots were taken tripod mounted and what you see here is a 100% crop from the center of the image:
Now everyone has their own ideas about image noise but to me the 100 and 200ISO images look great. At 400ISO there is visible noise but not bad. By 1600ISO the noise is obvious and 6400ISO is really only for those who want a Seurat-like look to their images.
Using our histogram test you can see how the peaks are fairly tight at 100ISO but show the clear signs of noise spreading at 400ISO.
Overall I think Pentax have done an amazing job of controlling daylight type exposure noise levels in this camera, given its resolution and sensor size (1.5x multiplication factor).
With night exposures (above of the test strip) of 15 seconds the same picture emerges.
As you can see from the night histograms above, even the 100ISO peaks have spread, but not as much as one might expect.
Pentax are to be commended for this camera. It is solid, ergonomically sound and takes great images. It also has well controlled noise given the resolution and sensor size.
I can recommend that people carefully consider the Pentax K20D.
RAW (PEF) images for our test shots are available from the camera test page.
Our infrared photography tests of the K20D are here.
If you are after a K20D I can recommend B&H Photo in NY, our preferred US camera equipment supplier.