Pentax Q Mirrorless Digital Camera Review$799.00
The Q does not allow the user to turn noise reduction completely off, but allows the choice between automatic, high, or low. The highest noise reduction setting keeps noise at or under 1% all the way through ISO 6400, where it only hits 1.04% by our testing. That's fairly aggressive by interchangeable lens camera standards, but the Q does retain a good deal of fine detail even at this setting, completely wiping away most signs of image noise. The automatic setting sits between low and high, and doesn't ramp up noticeably throughout the ISO range. It would likely be more useful if it were named "medium" instead of "automatic," but all the modes do their job without allowing noise to overpower the image. More on how we test noise.
The Pentax Q offers an ISO range of 125-6400 in 1/3 stops. ISO can be controlled by pressing the top button on the rear four-way control pad and adjusting the rear control wheel. Also selectable is an automatic ISO mode, which will choose a setting between a user-defined range. That range can be as large as ISO 125-6400 or as small as 125-160, giving users finer control over how the camera automatically selects exposure.
The Pentax Q utilizes a 25-point contrast detection autofocus through the lens, with a sensitivity of 1-18 EV at ISO 125. The focus is snappy, though it's not the fastest that we have seen. We found the Nikon J1 and the Olympus E-P3 were faster for mirrorless cameras, though the Pentax Q comes in very close behind those two. There are also focus options for face detection, subject tracking, and precise point selection, though all modes struggle a bit in very low light.
The Pentax Q performed well in our long exposure tests, though we found its 8mm f/1.9 kit lens' limited aperture range caused it to overexpose images. There is little that Pentax could do, as an f/22 aperture with such a small sensor isn't practical. In general, though, the Q actually outperformed our comparison group in long exposure testing despite those technical hurdles. More on how we test long exposure.
The Pentax Q had a color error of 3.3 in bright light testing, and that error only increased to between 3.8 and 4.0 in longer exposures. We found that noise fell off dramatically in exposures longer than one second, suggesting that the Q may be ramping up noise reduction when the camera is set to take longer exposures. There is no specific long exposure noise reduction feature, merely the high ISO noise reduction option we tested for our noise section. We shot all our long exposure test shots at ISO 400, however, and found that the noise totals returned in our long exposure results had approximately 30% less noise than comparable ISO 400 shots taken in bright light testing. Due to this, we believe the Q is applying heavy noise reduction (more than even its high ISO noise reduction setting's maximum) automatically to counteract any heat issues caused by utilizing a smaller sensor.
The Pentax Q scored the highest among all our comparison cameras, with minimal difference between bright light testing and low light, long exposure testing in terms of color error and noise totals. We could not deactivate the long exposure noise reduction in the Pentax Q (the camera doesn't give the option to), but found the camera's automatic long exposure noise reduction settings produced the least noisy images, though some fine detail is lost in the process.
Video: Low Light Sensitivity
The Pentax Q, despite its small sensor, needed just six lux of light for it to register 50 IRE on a waveform monitor. This is right in line with what we typically see out of interchangeable lens cameras with much larger sensors. Beyond that, noise did not increase appreciably, so if the camera was greatly boosting ISO sensitivity in order to achieve that result, it did not greatly detract from the image.