As is fairly typical of most digital SLR's the *ist DS performed pretty much perfectly in natural light (outdoors, either sunny or overcast) but less well in artificial light. It's worst performance by a large margin was in incandescent light where there's a very strong red/orange color cast which would be difficult to remove.
Outdoor - Auto WB
|Fluorescent - Auto WB
Red: -1.2%, Blue: -4.3%
|Incandescent - Auto WB
Red: 11.6%, Blue: -14.2%
Long Exposure noise reduction / Night shots
The *ist DS allows for timed long exposures of up to 30 seconds, beyond this you can use the dedicated Bulb mode, the *ist DS has a terminal for a wired remote release. The camera's optional noise reduction employs the typical 'dark frame' system we're used to, a second frame is taken with the mirror down and shutter closed, this is used to map 'hot pixels' which are then removed from the image. Without noise reduction a 30 second exposure had a liberal sprinkling of 'hot pixels' which we neatly removed (without any black pits or artifacts) in the same shot with noise reduction enabled.
|Noise reduction Off||Noise reduction On|
|ISO 200, 30 sec, F13||ISO 200, 30 sec, F13|
Overall results from the *ist DS built in pop-up flash were fairly good, color balance was good with no obvious color cast. Flash metering tended towards under-exposure but this could be corrected easily using the flash exposure compensation option in the record menu.
|ISO 200, 1/60 sec, F2.5|
|ISO 200, 1/80 sec, F5.6|
Overall Image Quality / Specifics
In use the *ist DS is such a nice camera, small and lightweight with a great viewfinder, responsive performance and fairly sensible control layout. It's a disappointment then that Pentax equipped the camera with such poor in-camera image processing. Because of its target market the *ist DS is likely to be used mostly by people shooting JPEG, as we've demonstrated on earlier pages of this review there's a vast difference in resolution and detail between JPEG and RAW and it's obvious therefore that a lot of the detail captured by the sensor is lost by the in-camera processing if you shoot JPEG. Otherwise image quality is good, with a more consumer-based target market the images are punchier with a higher contrast tone curve and more saturated colors by default (you can of course tweak this). Noise levels were low, on par with other digital SLR's although perhaps at the expense of detail at higher sensitivities.
Shoot RAW to see what the camera is capable of
Below you can see three images, the first shot as a JPEG from the camera, the next two converted from a RAW shot of the same scene. It's worth noting that because the *ist DS doesn't have RAW+JPEG we couldn't shoot the images at exactly the same time so alignment is slightly different, however the size of elements in the image are the same (height of tower in pixels for example).
|JPEG||Adobe Camera RAW||Lab Bright (RAW)|
As you can see from the 100% crops below shooting RAW and converting using either the supplied Pentax Photo Laboratory or Adobe Camera RAW yields the best results, better definition of fine detail, sharper edges and more film-like and less 'processed' look to the image.