The ability to successfully manage shadow noise on a per pixel level can be of interest, particularly when comparing cameras that use the same sensor size - in this case APS-C - but offer different resolutions. In the example below we're comparing the Pentax K-30 against the 18MP Canon EOS 650D and the higher resolution 24MP Nikon D3200.
We've taken base ISO Raw shots of our studio test scene and processed them in Adobe Camera Raw with a +3.0EV exposure adjustment. We've then taken crops in the darkest areas of our scene to compare the amount of shadow noise between the two cameras.
|Pentax K-30 ISO 100: ACR +3EV, NR off||100% crop|
|Canon 650D ISO 100: ACR +3EV, NR off||100% crop|
|Nikon D3200 ISO 100: ACR +3EV, NR off||100% crop|
Looking at the 100% crops above, it is clear that the Pentax K-30 displays less more chroma noise than both the Canon EOS 650D and the Nikon D3200, although the difference to the latter is much smaller.
Real world sample
While the results of our studio scene reveal interesting information about the sensor's maximum capabilities, it's important to place those results in the context of real-world photography. Below is an image shot outdoors under typical daylight conditions at ISO 100. We've taken the same raw file and converted it twice in ACR 7.2 - once at default exposure settings and again with three Basic Panel adjustments, detailed below.
|ACR 7.1: Default settings with NR off||ACR 7.1: Shadows +72, Blacks -14, Highlights -20 with NR off|
|100% crop||100% crop|
As you can see with the K-30's Raw files it is certainly possible to gain significant shadow detail while maintaining a reasonable overall exposure by opening up the shadows in ACR - without significantly increasing the shadow noise. This gives you enormous flexibility when editing Raw files and allows you to create almost HDR-like images from only one exposure. In terms of shadow noise the K-30 is no doubt one of the best APS-C camera we have seen until now.
On the Pentax K-30 you have the option to enable distortion correction in the Control Panel. As you can see in the images below, the feature does a good job at keeping the image from showing the barrel distortion caused by the lens. This shot was taken with the 18-135mm lens at its widest focal length.
Overall the distortion correction is doing an excellent job, eliminating a large portion of distortion with only a minimal loss of quality at the edge of the frame. You also lose a small portion of the frame around the edges to the correction.
With this feature activated the number of frames in a burst and the buffer full rate during continuous shooting decrease significantly. So make sure you switch Distortion Correction off when shooting bursts. You can read more about this on the performance page of this review.
Distortion Correction On
Distortion Correction Off
Overall Image Quality
The K-30 uses a further developed version of a sensor that we very impressed with when we first saw it in cameras like the Pentax K-5 and the Nikon D7000. There are now various APS-C cameras around with a higher resolution than the K-30's 16 MP but the Pentax image output still offers enough detail to satisfy most needs. To many photographers the extremely low noise floor will be of higher practical importance than pixel-count anyway. It makes the K-30's Raw files extremely malleable, and allows for an awful lot of flexibility in post-processing - something that photographers could only have dreamed about only a few years ago.
In addition to the low shadow noise levels at default settings and low ISOs, the K-30 captures high levels of detail, even in low-contrast areas of the frame. In the camera's JPEG output first signs of noise appear in areas of plain tone at ISO 400, but you have to zoom in to 100% magnification to spot it, which makes it pretty much irrelevant in practical terms. At ISO 800 upwards, though, the detrimental effects of noise-reduction on fine detail become more visible. As you would expect image quality deteriorates further as you go up the ISO scale, but output remains very usable up to very high sensitivities. However the very highest ISO 25600 setting should probably be reserved for web-use and smaller output sizes only. That said, the K-30 performs generally very well at higher sensitivities and compares very favorably to its peers in this area.
Detail can be further enhanced by processing the camera's Raw files and applying custom sharpening parameters. Raw processing also allows for a customized approach to noise reduction and, as mentioned above, for heavy editing of the images' tonality, thanks to the very low noise floor. Overall the Pentax K-30's image output leaves very little to complain about, and is among the best we have seen from any APS-C sensor camera so far.