Here you can see a generated GretagMacbeth ColorChecker chart, place your mouse over any of the labels below it to see the color reproduction in that mode. Select a camera/setting combination from the 'Compared to' drop-down to comparative boxes inside each patch.
Being a 'semi-pro' camera Pentax chose to use the 'Natural' image tone by default rather than the frankly over-saturated 'Bright' setting used on the *ist and K100D/K110D. This leads to neutral and representative color balance which should never suffer from color clipping in any channel, even with brightly colored subjects. This Natural image tone is actually quite close to the default output from the Canon EOS 30D and Sony DSLR-A100.
Adobe RGB Natural
Artificial light White Balance
Just as with the K100D the K10D's automatic white balance performance in artificial light left a lot to be desired, although to be fair this is nothing new with digital SLRs. The key here is to use the white balance presets or better still take a manual measurement from a white or gray card.
Incandescent - Auto WB
Red: 7.1%, Blue: -16.6%, Poor
Incandescent - Incandescent preset WB
Red: 0.3%, Blue: 3.0%, Good
Fluorescent - Auto WB
Red: 0.1%, Blue: -1.8%, Excellent
Fluorescent - Fluorescent preset WB
Red: 4.7%, Blue: -14.8%, Average
Long Exposure noise reduction / Night shots
A typical thirty second long exposure (night shot) at ISO 100 without noise reduction did produce a few hot pixels sprinkled around the image, although not so much as the K100D. Enabling the 'dark frame subtraction' noise reduction (which is on by default) eliminated these and left no black pits or any other artifacts.
Noise reduction Off
Noise reduction On
ISO 100, 30 sec, F10
ISO 100, 30 sec, F10
A typical 'modern digital SLR' performance, no color cast or white balance issues, good exposure in a portrait shot with well metered flash power and slightly under-exposed shooting our color chart (because of the white background). Overall, good.
Overall Image Quality / Specifics
The K10D delivered good results with plenty of detail and a neutral, smooth appearance to images which gives them a more film-like appearance although could also be described as slightly 'soft'. Color was nice and neutral and you always have the option of either increasing saturation or selecting the Bright image tone for punchier images straight out of the camera. Noise levels were also good up to ISO 800 although slightly higher than we would have hoped at ISO 1600, that said detail is maintained thanks to a 'hands off' approach to noise reduction. We have read some discussion about 'banding' at ISO 1600, we didn't have any good examples of this in our everyday shots, it was possible to take a very dark shot and see some hint of banding in the red/blue channels but it's pretty unlikely this would be visible viewed on a screen or in print (it's certainly not a stand-out issue).
Image sharpness / demosaicing (JPEG vs. RAW)
We were a little disappointed that the K10D's built-in image processor didn't deliver the crisp sharp edges which can be produced by shooting RAW and converting using a third party engine (such as Adobe Camera RAW). It's speculation but it does appear to me to be a combination of the type of demosaicing algorithm used (not isolating edge detail well enough) and the type of sharpening algorithm (as discussed earlier this appears to work to enhance the 'undershoot', the black side, of an edge). As we saw in the Image Parameters section of this review increasing sharpening only appears to increase the visibility of texture type detail rather than edge sharpness.
Below you can see a comparison using our standard studio scene between JPEG straight from the camera and a RAW converted using Adobe Camera RAW (as per our normal RAW converter settings, no sharpening and then a 80% unsharp mask applied after conversion).