Dolby Laboratories DA20, Руководство по установке

Страница: 106 / 122

6-1
SECTION 6
OPERATING INSTRUCTIONS
6.1 How to Identify Sound Tracks on Prints
6.2 Film Threading
6.3 Displays
6.4 Format Control
6.5 Auliliary Data Channel
6.6 Two Projector Changeover Operation
6.7 Operation With An Automation System
6.1 How to Identify Sound Tracks on Prints
A Dolby Digital film print or a stereo optical print (A-Type or SR), or a mono optical print
should be identified as such on both the film can and leader. However, with handling the
identification may be lost. If you are not sure if you have a stereo analog print, play a reel
and find a section with music and/or effects only (on dialogue or narration, stereo
soundtracks look much the same as mono soundtracks). Examine the soundtracks
closely; on music and effects, the two soundtracks will appear to be different on a stereo
print; on a mono print they are identical. If you specified a stereo print and received a
mono print in error, be sure to check with your local exchange or the film distributor.
a
aa
a
a
aa
a
a
aa
a
Dolby Digital Print
The digital data blocks are
clearly visible between
perforations next to the
analog track. The analog
track is Dolby SR encoded.
Analog Dolby Stereo Print
Clear differences between
channels will be seen in some
places along the track.
Mono Print
Both tracks are the
same.
Figure 6.1 Film Sound Tracks
There is no way to tell by visual inspection if a stereo print has been encoded with a
surround channel or whether it is Dolby A-type or SR encoded. However, all but a few
early Dolby Stereo releases do have a surround channel. The majority of prints are now
Dolby SR encoded. If you are in doubt, play the print in format 04 Dolby A-type until
you have a chance to listen to the track and compare playback quality in formats 04 and
05.
6.2 Film Threading
The Cat. No. 700 Digital Soundhead is similar in many ways to a conventional analog
soundhead, having a lightweight flywheel, toothed sprocket, two pad rollers, and two