Great camera, but the SPK-AS2 underwater case is useless

This review refers to the version of the Sony HDR-AS100, which is supplied with a Bike Kit. Before I Bike Kit, I want to write a few things about the camera itself.
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THE CAMERA

*** Features ***
The first thing that strikes you when this camera is that it is incredibly small and light. Despite its size, it has some impressive features, including slow motion recording at 50fps in Full HD quality and up to 200 fps at reduced resolutions. If you have updated to the latest firmware version, you will also be able to use the camera for live streaming over the Internet.

*** Shooting at high bit-rate ***
Another interesting development is the inclusion of a high bit rate in XAVC-S-record format for much better picture quality. The bit rate when shooting at 50fps is not doubled, so that the quality will deteriorate at some slow motion shots. The only downside of XAVC-S is that a Class 10 Micro must use SDXC card. The camera allowed in this format no Micro SD or SDHC card (not the class 10). However, if you want to record in a format with lower bit rate, you can also use other cards.

*** Compared with the GoPro ***
If you have not yet decided between the Sony HDR-AS100 and the GoPro Hero3 + Black: the GoPro beats the Sony regarding sharpness. Your objective is also less distortion and gives you more control over exposure settings. On the other hand, the Sony better image stabilization on, shows more detail in the shadow areas of your images and provides much better audio recordings for a lower price.

*** Unterwassergehäuse ***
As far as I can tell, all versions of the HDR-AS100 (including Bike Kit version) come with the SPK-AS2 underwater housing. However, this is unsuitable for underwater video, because the case is in front, where there is the lens covered, arched. Thus, it acts like a lens, and when dipping the camera to the housing into the water, everything is blurred. It is better to see this case as protection against splashes or accidental immersion in water, rather than to use it for recording underwater. If you want to make crisp, clear underwater photos, you need a housing having a flat lens cover. Sony's MPK-AS3 housing is an alternative that has a flat lens cover and waterproof is also up to a greater depth. I can imagine that Sony eventually brings out a flat replacement cover for SPK-AS2, as the company has done for the SPK-AS1-housing. Until then, the SPK-AS2 Unterwasssergehäuse Camera enhances barely.

Earlier Underwater Housing for GoPro cameras have incidentally had the same problem, until the company has changed the design. However, Sony is not the only company that repeatedly GoPro's fault.
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BIKE KIT

The Bike Kit for HDR-AS100 does not include much more than the non-kit version. The only difference seems to be that it comes with a roll bar mount and a few head mounts. It does not come with the RM-LVR1 Live View remote control, but you can watch a live feed from the camera when using a smartphone with the PlayMemories Mobile app from Sony. This app you get free for Apple and Android devices.

*** Rollbar mounting ***
When I mounted the HDR-AS100 means rollbar mount on my bicycle, I initially had some problems with excessive vibration. I have the rollbar bracket then attached so that it hangs instead of standing up, which worked a lot better from the handlebars down. I have also one of my bicycle brake cable wrapped around the mount, which helped dampen the vibrations. If you do not give these things overnight, vibrations along the bracket can be enhanced, which can not be adequately treated with the image stabilization of the camera.

The rollbar bracket is also useful for attaching a smartphone, so you can see the wireless transmission from the camera to this. If you place the camera on an extension, you can for example use the rollbar mounting it to mount a smartphone at the other end to see what you are filming. To do this, you need a smartphone attachment that can connect to a tripod socket.

*** Other holders ***
The headband is comfortable, but not what you want to wear when you walk down the street. You can pull the tape by a helmet or use the adhesive mounts for helmets without holes. It has thus plenty of options on how to mount the camera on the head.
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SUMMARY

The HDR-AS100 is a great action camera with some very impressive features. The SPK-AS2 underwater case is unfortunately of little use, so you have to buy another case, if you want to shoot underwater videos. The bike kit has a few useful additional components, but given how limited is the benefit, the price difference for non-kit is hard to justify.