A telesync (TS) is a bootleg recording of a film recorded in a movie theater, often (although not always) filmed using a professional camera on a tripod in the projection booth, the audio of a TS is captured with a direct connection to the sound source (often an FM microbroadcast provided for the hearing-impaired, or from a drive-in theater). Sometimes the bootlegger will tape or conceal wireless microphones close to the speakers for better sound quality.
The true definition of telesync would include the film being synchronized to the camera's own frame rate and shutter timing as done by television companies when preparing celluloid film for broadcast. A bootleg TS rarely, if ever, uses this form of synchronisation which can lead to additional temporal aliasing. A TS uses cam video with better-quality audio. 
As technology gets better, the quality of telesyncs also improves, although even the best telesyncs are lossy and will be inferior in quality to direct rips from Blu-ray, DVD or digital transfers from the film itself (see telecine). Although very few at the moment, some release groups use high-definition video cameras to get the clearest picture possible.
- afterdawn.com. "Glossary for film piracy terms".
- Craig2005 Craig, Paul; Ron, Mark (April 2005). "Chapter 8: The Piracy Scene". In Burnett, Mark. Software Piracy Exposed - Secrets from the Dark Side Revealed. Publisher: Andrew Williams, Page Layout and Art: Patricia Lupien, Acquisitions Editor: Jaime Quigley, Copy Editor: Judy Eby, Technical Editor: Mark Burnett, Indexer: Nara Wood, Cover Designer: Michael Kavish. United States of America: Syngress Publishing. pp. 162–165. doi:10.1016/B978-193226698-6/50033-7. ISBN 1-932266-98-4. Lay summary. "A telesync is a film recorded on a professional camera (often a digital beta-cam).The cameras are placed on steady tripods and the ﬁlms are recorded in an empty cinema from the main projection booth. The sound is often recorded straight from the mixing board, giving the telesync a high quality of sound. Some releases even include surround sound in Audio Compression 3 (AC3) format. Telesyncs are the most common of early releases, often being the first release a movie site accepts. Telesync movies are easier to watch than their CAM counterparts, although the picture quality is usually slightly washed out and the contrast is often out of balance. Telesyncs are commonly traded on movie sites. They are the lowest quality allowed, but are still popular with many file traders."
- Krömer, Jan; Sen, Evrim (2007) . "Chapter 3: All You Can Eat". No copy: die Welt der digitalen Raubkopie [No copy: the world of digital piracy] (in German). Germany: Tropical Publisher. pp. 110–111. ISBN 3‐932170‐82‐2 .
- Telesync on Afterdawn