Pentax K-5 review
Pentax K-5 review - Image Quality
Pentax K-5: Tone & Exposure
The K-5 feels fundamentally different to its predecessors, particularly in the exposure stakes. Whereas a common observation has been for slight underexposure, the K-5 bucks this trend by providing exceptional metering and exposure. Indeed a number of shots required the exposure compensation to be dialed down a third of a stop at times in order to hold just that touch more highlight detail.
Tonally shots can come across a little flat at times, though this is perfectly adept for life-like realistic prints, but may not have quite the level of expected punch on screen.
Pentax K-5: RAW/JPEG
It's possible to shoot either Pentax's 14bit PEF Raw format or select the more universal Adobe DNG format. Whichever you choose is of little consequence to final quality.Pentax K-5 review test sample image - click for full size gallery
The JPEG files show a degree of added contrast and brightness in processing, as well as pixel smoothing to limit the presence of image noise. At the lower ISO settings this produces a more appealing final image than the untouched Raw file, though at higher ISO settings it's a different story: the Raw files, without any noise reduction applied, are far grainier, yet don't suffer from any limitation to sharpness and should be the files to work with if high ISO shots are generally what you work with.
Pentax K-5: Colour & White Balance
Colours are punchy to look at, but not overly so. A little added saturation in post-production makes for greater vibrance for screen-based work. Outside of the ‘standard' shooting mode, however, there's an abundance of Digital Filters, including an HDR Capture mode and even in-camera Cross Processing. These are potentially great when shooting JPEG only, but frustratingly cannot be applied when shooting Raw + JPEG. Of course, if this were possible, the Raw file would still be the original and untouched version, but it would be nice to have the option of in-camera adjusted JPEG and original Raw file available in tandem.
Auto White Balance was generally accurate - warmer for interior shots, a little cooler and more neutral for exteriors, but pleasingly so on all accounts of our testing.
Pentax K-5: ISO Sensitivity & Image Noise
The new sensor coupled with the K-5's processing does an absolutely fantastic job of handling image noise. At the lower ISO settings the K-5 provides quality that can easily rival the Canon 60D and Nikon D7000. Where it gets extra special, however, is in the mid-high ISO settings where the processing does an exceptional job of keeping colour noise to a minimum. Granted this is going to be at the expense of sharpness as the ISO increases, but up to ISO 3200 images can still be taken of an acceptable quality.
Pentax K-5 review sample image: ISO sensitivity image noise test - click for full size gallery
There is some presence of colour noise from as low as ISO 400, particularly in the shadow and black areas, but this doesn't become problematic until the particularly high ISO settings.
Although the option of ISO 51,200 was added at the last minute (the pre-release model was set to top-out at ISO 25,600), it has to be said it doesn't really add any value. The top two to three most sensitive settings (ISO 12,800-51,200) will have limited use due to the significant presence of luminance noise.
All in all, if these results were pitched side by side against similar-spec cameras then they would more than hold their own. Very good quality indeed.
Pentax K-5: Sharpness & Detail
Similarly to ISO sensitivity, detail diminishes pretty quickly when heading to the upper settings. ISO 51,200 delivers little discernable detail, but dip into the lower ISO 80-800 and hair-line detail can be seen, even to some degree at ISO 1600.
The 18-55mm WR kit lens is reasonable in terms of sharpness, though the previous versions we've tested have been just ever so slightly less sharp than the non weather-sealed versions (though for real world imaging this is unlikely to cause any discernable difference). Of course there are many other Pentax lenses, old and new, and the sensor at the heart of this camera is more than capable of delivering the detail in droves: the better the lens you can get hold of, the better your results can be.