In low light the difference in results from the tiny sensor of the Pentax Q and the 8 times larger sensor of the Olympus should become more prominent. Let's take a look and see what we find.
One objective of this review is to determine if the smaller but back-lit sensor in the Pentax Q can compete with the much larger, old technology sensor used in four thirds compact ILC cameras, represented here by the Olympus E-PL3. The two cameras have the same resolution, 12 MP, so comparing resolution will not tell much. More critical is high ISO noise. We do not expect that the Pentax Q's much smaller sensor is a match for the four thirds sensor, which is a full 8 times larger in area! The tests below will reveal how the Q stacks up.
These test images were shot in JPG with the default settings for noise reduction. We increased exposure of the Pentax Q images by about 0.5 stops. The images in the drop down represents 100% crops of a low light scene - the light source was one 300W halogen bulb reflected off the ceiling. We used the 17mm prime lens for the Olympus and the 02 Standard Zoom for the Pentax Q, set at 6.1mm to match the field of view of the Olympus. We used F5.6. Both cameras were set for auto focus.
Note that the Pentax's sensitivity starts at ISO 125 and goes up to ISO 6,400, whereas the Olympus starts at ISO 200 and goes up to ISO 12,800.
Both cameras are doing a very good job of noise suppression. We attempted to better the Pentax by processing the 6400 ISO image from a RAW file and applying Topaz DeNoise 5, but we could not beat the processing done by the camera. The Olympus produces cleaner images at low ISO and its noise at ISO 3200 is about the level of the Pentax at ISO 800; the Olympus has about a 1.5 to 2 stop advantage over the Pentax. Even then, the Pentax Q can be used in a pinch all the way up to ISO 3200, whereas ISO 6400 is much too noisy.