The lenses of the cameras are removed and then these are attached to telescopes to record images, video, still, or both.
In newer techniques, videos of very faint objects are taken for a couple of seconds and then all the frames of the video are "stacked" together to obtain a still image of respectable contrast.
Researchers claim that this method is accurate to within 5 bpm.
Webcams may be installed at places such as childcare centres, offices, shops and private areas to monitor security and general activity.
They have also become a source of security and privacy issues, as some built-in webcams can be remotely activated by spyware.
Mostly, these are manual-focus cameras and contain an old CCD array instead of comparatively newer CMOS array.For a more complete list see Comparison of webcam software.Special software can use the video stream from a webcam to assist or enhance a user's control of applications and games.Video features, including faces, shapes, models and colors can be observed and tracked to produce a corresponding form of control.For example, the position of a single light source can be tracked and used to emulate a mouse pointer, a head-mounted light would enable hands-free computing and would greatly improve computer accessibility.
When sent to a remote location, the video stream may be saved, viewed or on sent there.