The HDR-AS15 is a tiny, plastic camcorder that comes with a see-through waterproof case (up to 60 m deep) and two adhesive mounts. For an added fee, you can get an elastic headband for attaching the camera to your head or helmet. The camera itself is ultra-light (83 g, including the battery and memory card).
The problem is that the ovoid shape means it can't sit upright without some sort of stand or base to support it. Since there's no screw hole to mount it on a tripod, if you want to sit the camera up you have to resort to the waterproof case, even if you're not going in the water. With the case on, it weighs 160 g and you lose all access to the audio in, HDMI out and microUSB port. So while the microphone input is a good idea, in practice it often ends up being unusable. Same goes for the microUSB port, which serves for unloading videos and charging the battery. And without the case on, the only way to mount the HDR-AS15 on a tripod is to use a clip (sold separately).
Left: monochrome control screen. Right: battery and memory card slots in the back.
Left: the waterproof case can be clipped to a tripod. Right: Connectivity on the underside (mic, mini-HDMI, micro-USB).
The interface is as simple as possible: three buttons and a basic, text-only LCD screen. It's a barren design, but with a little experience the HDR-AS15 becomes easy to customise. Every time you confirm something in the menu a rather indiscreet tone is played that you can't get rid of. But the real problem, of course, is once again the waterproof case, which blocks your access to the menu, so you have to set up your options before heading out on an escapade.
The HDR-AS15 records in 1080p at 30 fps (H.264 compression) and in 720p at a range of speeds for slow motion shots: 30, 60 and 120 fps. There's also a 640 x 480 VGA mode. Another option lets you take still photos at regular intervals (5, 10, 30 and 60 seconds). The stills are in 1920 x 1080, but unfortunately the picture quality doesn't do justice to the sensor's 12 Megapixels.
In 1080p/30 fps mode the battery gives you just barely an hour of shooting. That's if you don't go mucking around in the menu. Or turning on the Wi-Fi. In short, if you're going out on a trek, think to bring a backup battery (or two). The battery takes about an hour to charge, via USB.
The HDR-AS15 has an image stabiliser, but it's digital and it reduces the viewing angle from 170° to 120°. The result is nothing extraordinary. But I guess a bad IS is better than no IS. The picture quality from the 1/2.3" sensor narrowly cuts it for an action cam. The images have great contrast, but they cruelly lack detail. The HDR-AS15 also has a certain tendency to overexpose scenes and blow out any brightly lit parts of the frame. It may not be mindblowing in dark settings, either, but the BSI sensor does do a tad better in low lighting than competing action cams.
At the end of the day, the image quality is far, far from what an ordinary camcorder will give you for the same price. But let's be indulgent: chances are good that most of the videos will end up online anyways, where these shortcomings won't be as obvious as on a TV.