Normal Operation - Christie 35/70 Maintenance And Service Manual

F i l m P o s i t i o n
Two counters are stored in the projector memory space to track the position of the film. These are referred to as the reel
counter and the film counter. The reel counter tracks timing for an entire reel of film, whereas the frame counter tracks the
timing within an individual show. Both counters are expressed as a composite measure of time and frame position in the
form hh:mm:ss:ff, where:
hh =
hours (0 - 99)
mm = minutes (0 - 59)
ss = seconds (0 - 59)
ff = frame count within the second, called frame number (0 - 29).
The frame counter begins counting at the beginning of each show, and measures 30 frames for each second. By
convention, each show's starting time is set to one hour and zero frames. This is displayed as 01:00:00:00.
The reel counter begins counting at the beginning of the reel. It also measures 30 frames for each second, and is initially
set to 01:00:00:00. However, unlike the frame counter, the reel counter is not reinitialized at the start of a new show. The
value of the reel counter is the cumulative, or elapsed, time-and-frame from the start of the reel.
The frame counter display on the control panel (see Section 0) normally shows the frame counter. See Sections 0 and 0
for discussions of changing this display to and from the reel counter value.
An example of reel and frame positions is shown in Table 2.1. For simplification, it is assumed that the BOF for Show #1
and the start of the reel are at the same position. Using the figures from that example, if the reel counter and frame
counter were compared at the point that is 2 minutes, 37 seconds, and 15 frames into Show #2, their values would be:
Reel Counter:
Frame Counter:
Reel Contents
Show #1
Separation between shows
(from EOF #1 to BOF #2)
Show #2:

Normal Operation

When operating normally, the projector is a completely automatic unit; once loaded with film and initially framed, it
requires no operator. The projector automatically sets the loop size, reframes the film in the gate, cues to at the head of
the desired show, and waits for a command that will cause the projector to play the show. When that command is re-
ceived, the projector accelerates the film to cine speed in a smooth linear manner, synchronizes the pulldown with the
shutter, and looks for the first frame of the show. When the first frame is found, the douser is enabled, and the projector
signals the show controller that play is beginning. The douser open command may now be issued or, if the AUTO
DOUSER function is enabled, the douser will open automatically 3 seconds into the film.
The douser closes automatically when it reaches the end of the current show. If the next show has not already been
identified to the projector, the film decelerates to a stop in a smooth linear manner, and waits for a command that sets the
next show. When the next show is identified, the projector moves at two times the normal speed (120 fps), cues to the
CHRISTIE INC. - 35/70 Service/PM Manual
July, 1997
01:06:55:19 (3:52:14 + 0:16:20 + 2:37:15)
01:02:37:15
Length
00:03:52.14
(hh:mm:ss.ff)
500 frames
(00:00:16:20)
00:04:27.02
(hh:mm:ss.ff)
Table 2.1: Reel Counter and Frame Counter
2 . G e n e r a l D e s c r i p t i o n
Reel Counter Frame Counter
Start/End Start/End
01:00:00:00 01:00:00:00
01:03:52:14 01:03:52:14
01:03:52:14 01:03:52:14
01:04:09:04 01:04:09:04
01:04:09:24 01:00:00:00
01:08:36:26 01:04:27:02