Noise, resolution and sensitivity
These images show 72ppi (100% on a computer screen) sections of images of a resolution chart, captured using the 18-55mm f/3.5-5.6 kit lens.
We show the section of the resolution chart where the camera starts to fail to reproduce the lines separately. The higher the number visible in these images, the better the camera’s detail resolution is at
the specified sensitivity setting.
With a refined version of the 16-million-pixel sensor that has received such praise in cameras such as the Pentax K-5 and Nikon D7000, expectations are therefore high for the K-30, a less expensive camera that sits lower down the range.
As with Pentax’s own K-01, our resolution charts show that the K-30 is able to resolve up to the 26 marker at ISO 100 in DNG raw format, using the 18-55mm f/3.5-5.6 kit lens.
To get the most possible detail from the camera, shooting in raw format is necessary. JPEG compression and sharpening come at the cost of fine detail on our charts, and at ISO 100 the camera reaches only the 24 marker. There are other cameras available with higher-resolution sensors that can resolve more detail than the K-30.
However, it is the Pentax camera’s low-light performance that is particularly impressive. Like the K-5, the K-30’s native ISO range is 100-12,800, although the K-30 has only one extended setting, up to ISO 25,600.
Resolved detail is largely uncompromised thanks in no small part to the camera’s ability to handle noise.
Without noise reduction applied in-camera, images are ‘clean’ all the way up to ISO 800, and only at ISO 1600 does luminance noise become noticeable in real-world images. In fact, images are acceptable all the way to ISO 6400, but at ISO 12,800 noise levels are problematic – detail becomes mushy, and tone flat.
Chroma noise is also evident at this setting in small yellow, green and red patches over the entire frame. The K-30, however, puts forward a good case for keeping a lid on resolution, in favour of
good performance in more challenging low-light conditions.
Image: Taken at ISO 400, this image has been brightened by +2EV and noise is still well controlled. Sharpening and contrast adjustments in the JPEG result in the loss of some details
