Performance and Image Quality
The Pentax Q7 starts up in just about a second. Shot to shot time in JPEG mode is just over a second, but shooting in Raw mode slows down shot-to-shot times noticeably, approaching two seconds with a Class 10 SDHC card. With a cheap 2GB SD card of no special class rating, shot-to-shot times were similar but write time to the card in Raw mode was extremely slow. A string of five Raw images required around 15 seconds to write, during which you're locked out of menus and image review. You can, however, keep shooting while images are being processed. With a UHS-1 SDHC card, Raw+ shot-to-shot times were about the same, but write time to the card was much speedier - we found that a string of 10 shots writes in under four seconds.
In terms of AF speed, the Q7 feels a touch slower than a Micro Four Thirds or other mirrorless camera. There's an auto focus lamp on board for focus in the darkest settings, though even with its help AF acquisition can approach two seconds in the very dimmest of conditions. On average in good lighting, the Q7 focused in around half a second with the 02 Standard Zoom - a decidedly point-and-shoot speed. AF was acquired about a tenth of a second faster with the brighter 01 Standard Prime under the same conditions.
Photographing participants of a parade moving toward and past the camera at a good clip, we didn't expect amazing AF performance and indeed the Q7 missed focus in this admittedly challenging scenario about half the time with face detection AF mode enabled. Occasionally, the Q7 would focus just slightly in front of or behind a static subject, too, even when face detection seem to have identified a target. Here's where the Q7 shows its size; it feels like a miniaturized Micro Four Thirds camera in some respects of its operation, but in terms of auto focus, it performs more like a point-and-shoot.
Continuous Shooting and Buffering
As advertised, the Pentax Q7 boasts a maximum burst speed of 5 frames per second though disappointingly, the screen blacks out and there's no live view as the shutter is snapping away. The first five frames are captured in a little under a second, but the buffer reaches its limit at that point and the Q7 will hesitate. In testing with a class 10 SDHC card and a UHS-1 Class 10 SDHC card, it sputtered a bit after this initial burst, varying between a slower one frame per second and snapping three or so at the same rate as the initial five. At its 'Low' burst speed setting, the Q7 shot roughly two frames per second with LCD blackout, without pausing to clear the buffer. LCD blackout in both of these shooting modes means tracking a moving subject will be nearly impossible. Important to note: Hi burst frame mode is not available in Raw or Raw+ shooting.
Image Quality (JPEG)
The little Q7 produces nice JPEGs. For the most part, default sharpening isn't overly aggressive and the results look natural. They're slightly soft at 100%, but are on par for the class. There's a lot to be gained by shooting Raw then applying your own sharpening or corrections, but more on that later.
At low ISOs and in good light, the Q7's images are competitive with those from enthusiast compacts and entry-level compact system cameras. The 'Bright' custom image mode will produce the punchiest colors. Shadow areas are darker and slightly more blocked up than in the 'Natural' mode, but it will bring out bluer blues in a sky and brighter greens from trees if that's what you're looking for.
As expected, the Q7 does fall victim to some common 'small camera problems'. The 02 Standard 5-15mm zoom and 01 Standard 8.5mm prime display some heavy barrel distortion, which is dealt with well in the JPEGs by in-camera correction but is very noticeable in the uncorrected Raw files.
In JPEGs, evidence of distortion or its correction is hard to spot. Detail at the very center of the 02 Standard Zoom is sharp, with a bit of a decline at the very corners of the frame. Raw shooters note that for now at least, you will need to apply your own correction for this rather dramatic distortion after the fact. According to an Adobe representative, support for the Q7 can be expected in an upcoming ACR update, but at the time of writing, Q7-specific lens correction profiles are not yet available (earlier profiles exist for some Q lenses but were created for smaller, older Q sensors).
The table below shows the performance of the standard zoom at its wideangle setting of 23mm (equivalent). We're showing the JPEG (automatically corrected in camera), the simultaneously-captured Raw file (uncorrected) and finally, our attempt to neutralise the distortion manually in Adobe Camera Raw.
Uncorrected Raw file
Corrected Raw file
Chromatic aberration cropped up more than once in our Q7 images, usually where we'd expect, in areas of high contrast and appearing in the form of a purple line between a light and dark area. It's noticeable in the worst cases in standard view on a computer monitor, but the majority of it is only noticeable at magnifications of 100% and upward. Both the 01 Standard Prime and 02 Standard Zoom produced images with noticeable fringing, in both Raw files and JPEGs.
We didn't see any more lens flare than expected from the 02 Standard Zoom. In some instances when it did appear, though, it was pretty dramatic.
|A noticeable purple flare appears in the glare on the building in this image. This type of lens flare only crept into a few of our hundreds of sample images, so it likely won't bother Q7 owners.|
The Q7 handles noise well at its default Auto Noise Reduction setting. Images from ISO 100 to 400 look good and don't show much evidence of aggressive noise reduction. Even shots at ISO 800 retain some level of detail, though viewing at 100% will show that low contrast detail is almost entirely lost and there are grainy digital artifacts present.
The Q7's built-in flash will recharge in around two seconds after a full discharge. It deploys in its 'at-rest' position or fully extended from the camera body. The flash extends above and slightly to the side, an ideal position to cut back on red eye.