content sourced from 1080-line HDV camcorders, but limits it to 15% of a whole program. Producers wishing to use HDV are required to submit an approved postproduction path outlining their handling of the footage in the editing process. The Discovery Channel HD simulcast has fewer or no guidelines and accepts a mix of XDCAM HD, HDV and AVCHD for the length of a program. For example, Discovery Channel aired 911: The Bronx, a six-episode reality series set in a hospital and shot with HDV cameras. Several episodes of Survivorman were shot with the Sony HVR-Z1U and HDR-HC3 camcorders. The Discovery Channel International uses rating system that defines Gold, Silver and Bronze acquisition and delivery levels. Depending on particular camera make and model and on post-production process, HDV footage can be rated as Silver HD, Bronze HD, or widescreen SD. In particular, some users consider Canon HDV camcorders to deliver the best-looking image with the least amount of compression artifacts among the models having 25 Mbit/s MPEG-2 HD codec. The PBS accepts HDV for widescreen programming acquisition and to a limited extent for use in HD programs. PBS may allow usage of "less than full broadcast quality equipment" if compression artifacts are "not obvious when viewed on an HDTV monitor". For example, the Art Wolfe's TV series Travels to the Edge was produced for PBS in HDV format using Canon XL-H1 camcorders. The Travel Channel HD eagerly accepts HDV footage. For example, Sony HDV camcorders were used for production of highly acclaimed Anthony Bourdain's No Reservations program, among other cameras. Bizarre Foods with Andrew Zimmern and its follow-up Bizarre World are shot with Sony HDV cameras as well. Madventures was shot with the Sony EX1 XDCAM EX camera paired with the Sony HVR-A1U HDV camcorder. Current TV used Sony HDV camcorders to shoot episodes for Vanguard TV series. Guiding Light, the longest-running soap opera in production in television and radio history, broke away from traditional three-sided sets and pedestal-style cameras in 2008, choosing the handheld Canon XH-G1 for shooting on practical locations until the show was canceled in 2009. Editing Because HDV video is recorded in digital form, original content can be copied onto another tape or captured to a computer for editing without quality degradation. Depending on capturing software and computer's file system, either a whole tape is captured into one contiguous file, or the video is split in smaller