The Raspberry Pi Foundation has been working on offering a camera attachment for Raspberry Pi boards for some time now. The developers began with a 41MP sensor, but have since moved to a smaller (and cheaper) camera with a 5MP sensor. That particular model is nearly complete and should be available for purchase sometime this spring, according to the developers.
The Raspberry Pi camera will be $25 which aligns itself well with the recently released Model A Raspberry Pi computer (which is also $25). The PCB hosting the camera module measures 20 x 25 x 10mm, while the camera module itself measures 8.5 x 8.5 x 5mm. It connects to the Raspberry Pi board via a flat cable into the CSI port below the Ethernet jack.
The $25 camera is capable of capturing HD video as well as stills. It uses the Omnivision OV5647 sensor and a fixed focus lens. The 5MP sensor is capable of capturing still photos with a pixel resolution of 2592 x 1944 and up to 1080p video. While the developers are still working on the kinks to ensure that it the camera can do this, the sensor itself is capable of 1080p30, 720p60, and 640x480p90 video capture. The Raspberry Pi Foundation has stated that at least the 1080p30 capture mode is working.
Interestingly, the Raspberry Pi ISP hardware can support two cameras, but the PCB only provides a single CSI connector (so no 3D image capture using two cameras). The Raspberry Pi Foundation is providing this little CSI camera as an alternative to USB cameras. While it is possible to use USB cameras with the Raspberry Pi, USB driver overhead and USB bandwidth issues specific to the Raspberry Pi limit the performance that you can get out of USB cameras. The $25 CSI camera add-on bypasses the USB interface in favor of the CSI port that feeds into the image processing parts of the ARM SoC.
The developers have not released an exact weight measurement, but have described it as being rather lightweight–making it ideal for use in drones, weather balloons, and other flying projects. For more information, the developers have set up a forum thread to answer questions and keep interested users updated on the project status.