|
||||||||
The following details are of a school show which was recorded on video early in 2002 by a group of year 10 boys. Cameras: Sony TR913Es are normally used, and these are fine so long as we only want to use two cameras. However, for the three camera shoot planned we would have needed three identical cameras, one more than was available. We tried incorporating older cameras such as a TR2000 or a TR707 into the line-up, but the colour balance was so different between the TR913Es and the older cameras that this was not a viable option. To add insult to injury, the colour balance of the older cameras (when set to indoor light using their manual white balance facility) was noticably better than the TR913Es which have only automatic white balance. We were
not able to find another TR913E which would have been
available to us on loan, so we opted for the higher
quality of the older cameras and borrowed a TR705, a TR707,
and a TR2000 (all Hi-8). These older cameras, which were
far more expensive in their day than the currently
available Hi-8 cameras, have larger CCD's than the
current crop. Some would say better lenses, too. The
pictures seemed to have better definition at all light
levels, and lower noise at low light levels than the TR913Es. These
observations also apply to the TRV320E (Digital-8) which
was one of the cameras tried as an alternative.
The block diagram above shows the basic layout of the system used. Camera 1 was the TR707, and was set up on one of the Velbon D-700 tripods in the gallery. Camera 2 was the TR705, and was set up on an identical tripod in it's usual place in the Hall (on the right hand side towards the front). Both cameras 1 and 2 were manually operated, the operators receiving their instructions from the Director via a microphone link to their headphones. In each case the microphone preamplifier in their camera was used to drive their headphones. Camera 3 (TR2000) was clamped in an inaccessible position about 12 feet above ground level, over the rear fire doors on the left hand side of the Hall. Because camera 3 was inaccessible it had to be set at the time of installation for an average of anticipated conditions - zoom, exposure, focus, and white balance - then powered up and and simply left. It was given a mains socket of it's own, and the plug was Gaffer taped to the socket and Gaffer tape was stuck over the switch. Thanks heavens we did not have a power cut between setting up and recording the show! Vision mixing: The school's existing Panasonic WJ-AVE5 mixer will handle only 2 camera inputs, so it was necessary to borrow a second such mixer and daisy-chain them. As will be seen from the diagram above, camera 1 was plugged into input 1 on mixer 1. Mixer 2 was plugged into input 2 on mixer 1, so mixer 2 supplied the cameras 2 and 3 signals to mixer 1. Camera 2 was plugged into input 1 on mixer 2, and camera 3 was plugged into input 2 on mixer 2. It sounds more complicated than it actually was. The 15 year old boy who was the Director and vision mixer got to grips with it from an operational point of view in about 10 seconds, and used it very competently. The purchase of a 4-input Panasonic MX50 would, however, be a good idea when funds permit. Sound: A Soundcraft Notepad mixer was borrowed for the recorded sound, as the school's own 12 channel sound mixer was being used by the pupils who were putting on the show. The main sound from the public address system was connected via the microphone transformer box to one of the mic. (XLR) sockets on the Notepad mixer. This reduced the level by 7:1 (about -17dB) and separated the earths of the 2 systems to prevent hum loops forming. The only other sound source from a recording point of view was a stand mounted Audio Technica MB3000 microphone at the front of the Hall, used to capture ambience and audience reaction. For the speeches of appreciation the Headmaster and the Show Supervisor used a clip-on radio mic. connected to the public address system, so the recording system picked this up via the main sound system. The output from the Notepad mixer was fed into the aux. audio inputs on the Panasonic vision mixer - this was done for level setting as the Panasonic unit has bar graph metering, whereas the Notepad has only average-level and overload LED warning lights. Monitoring - vision Cameras 1 and 2 operators used local Melford 12 inch monochrome professional grade monitors. A PAL encoded CVBS signal from each camera was taken first to it's local monitor which was set to "unterminated". The output or through signal socket on the local monitor then fed the link to the mixer desk. The Director and vision mixer used the Hitachi 14 inch colour TV sets for camera 1 and camera 2 signals, and the mixed output from the desk reaching the master VCR. In fact, the mixed signal was taken from the line-output sockets of the VCR rather than a monitor socket on the mixer, to prove beyond doubt that signals were reaching the master VCR. Camera 3 had no local monitor as it ran unattended, but it was monitored at the control room end on a borrowed Commodore 14 inch computer monitor. Monitoring - sound: During recording, sound was monitored for quality at the Notepad mixer on cans, and the levels were visually monitored on the level meters both on the Panasonic mixer desk and the JVC D-VHS machine. At the interval and after the show, some of the recorded signal was replayed via the "mix" monitor for picture, and the sound was auditioned using an old Trio amplifier from the Parents' Association and a KEF 103 loudspeaker donated by Meridian Studios. The sound and picture quality thus replayed was judged to be good. Master recording: A JVC HM-DR10000 D-VHS recorder was used for mastering, but as this was new and very much an unknown quantity a backup was set up using 2 Sony TRV320E camcorders which had been input-enabled for both DV and analogue signals. The Panasonic vision mixers each have 2 "S" video outputs in addition to 3 CVBS (composite - BNC) video outputs and 2 sets of stereo audio (phono) outputs, but of course only mixer 1 was used to provide these signals as mixer 2 was used solely as a switch box for cameras 2 & 3. One set of A-V outputs was taken to the input of the D-VHS machine, the other set to the analogue inputs, or more correctly input-enabled analogue output sockets, on the first TRV320 camcorder. This camcorder provided the A/D function and provided a digital output from it's DV socket. The DV-encoded signal thus obtained was fed via an IEEE1394 (Firewire/i-Link) cable to the DV socket on the second camcorder. The 4-way to 4-way IEEE1394 cable for this came packaged with the D-VHS machine, and was intended for connecting a DV or D-8 camcorder to the D-VHS machine for archiving purposes. Using Sony 8mm (not Hi-8) 120 minute cassettes (80 minutes in D-8 mode), the first camcorder recorded the first half of the show, and the second recorded the second half. Luckily each half of the show was less than 80 minutes, but as both camcorders were fed with the full programme it would have been a simple matter to load a camcorder with tape and start it up if it it looked as though the other one was about to run out. Both the D-VHS and D-8 masters were successful. Page last updated: 13 May, 2004 |
||||||||
