Pentax K-50 review – Noise, resolution and sensitivity
In terms of image resolution, the K-50 records about as much detail as you would expect for a DSLR with an APS-C-sized CMOS sensor. For all our resolution test images, the K-50 reaches around 24 to 26, with raw files having a shade more sharpness and detail than the equivalent JPEG produced in-camera.
What is more impressive is the camera’s handling of noise. As we have seen before, it is possible to really manipulate and adjust the exposure of images while introducing only a minimal amount of luminance and colour noise. Between ISO 100 and 1600, images are perfectly acceptable. At ISO 3200 and 6400, the luminance noise does start to become a little more visible, but given that many cameras will struggle at these sensitivities, the performance of the K-50 is very good. Above ISO 6400, luminance noise does become more of an issue, Although colour noise is extremely well controlled throughout the entire ISO range. When shooting raw images, I found that colour noise could be virtually eradicated in images taken at all the sensitivity settings.
In practice, I would feel comfortable shooting between ISO 100 and 1600 on a regular basis, and confident in the ability of the sensor to produce a good results even at ISO 6400. At high ISO settings image quality does start to break down a little, but even then the quality is impressive compared to many other cameras, particularly at this price and position in the market.
These images show 72ppi (100% on a computer screen) sections of images of a resolution chart, captured using the Sigma 105mm lens set to f/8 . 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.
