Video Systems

 

|Video Projector|Video Switcher|Laserdisk Players|SVHS Deck|Computer|Video Messernger|
| Planetarium | Planet Ops |

 

Overview

 

Many partial-dome special effects are most economically projected in a small dome by means of a three-tube RGB video projector (RGB = projecting superimposed red, green and blue images). Our video projector is installed in the Projection Booth projecting due east over the top of the star projector. The video projector is connected via the control devices to a high-end super videocassette player and two laserdisk players located in the audio rack, as well as to the PowerMac 8100 AV in the equipment room.

 

Video Projector

 

Turn on the video projector (VP) with the green button on the Switcher, or with the remote control.

Video Switcher

 

The Switcher receives video signals from the SVHS deck, from both Laserdisk players, from the PowerMac 8100 AV, and in the future from other sources (the unassigned ports may be used in the future for other builidings, cable TV, satellite feed, distance learning, etc.). It then sends these video signals to the Video Projector in the Planetarium Projection Booth.

Video projection system automation commands are as follows:

Command

Name

Description

LF

LAMP OFF

Turns Video Projector Off (very abrupt; abruptly turns off audio also)

LN

LAMP ON

Turns Video Projector On

#N

(0 ² # ² 8)

FADE VIDEO ON

Fade video signal on in # seconds

#F

(0 ² # ² 8)

FADE VIDEO OFF

Fade video signal off in # seconds (does not work with SVHS)

AFN#

(0 ² # ² 8)

AUDIO FADE ON

Fade audio signal on in # seconds (does not work with SVHS)

AFF#

(0 ² # ² 8)

AUDIO FADE OFF

Fade audio signal off in # seconds (does not work with SVHS)

SPLS

SWITCHER PULSE

Sets the Switcher Channel; use in conjunction with the SW# command (see below)

SW#

(0 ² # ² 8)

SWITCHER NUMBER

Selects the Channel Number for the desired video signal

Switcher channels (SW#) are assigned as follows:

 

  1. Unassigned
  2. Unassigned
  3. Unassigned
  4. Macintosh
  5. Unassiged
  6. SVHS
  7. LDA
  8. LDB

To play a video signal, make sure the Video Projector has been turned on and has warmed up. Then set the Switcher Channel to the desired video signal (e.g., from the SVHS deck) using the SPLS and the SW# commands together as shown below:

 
Wait long enough for the desired frame to be found, then:

SPLS

Switcher Pulse Switch

SW8

Switcher Channel 8

PLAY

Play

LDB

Laserdisk B

Laserdisk Players

 

The following commands may be sent to either laserdisk player, above (LDA) or below (LDB).

 

 

Project a video excerpt from a Sky-Skan disk as follows:

Note: Sky-Skan disks have STOP commands embedded at the end of each chapter.

 

FF2213 Find Frame 2213 LDB Laserdisk B

SPLS Switcher Pulse Switch SW8 Switcher Channel 8

(wait...)

PLAY Play LDB Laserdisk B

 

If both Sky-Skan disks are used for planetarium projection, it is customary to put #4 in LDB and #7 in LDA (note that SW7 is the switcher channel for LDA). This way multiple shows can be run the same day without having to flip the disks.

 

Send a Sky-Skan disk to the foyer or classroom monitors, repeating all chapters over and over with a LOOP script structure, as follows:

 

 

  1. Select the desired laserdisk and put it into the top laserdisk player.
      Tables of contents for the two Sky-Skan laserdisks are kept on top of the laserdisk players.

     

  2. Run the following script with Hercules (the VP need not be on). Note that it contains a loop within a loop, so that the Play command will be executed (999 x 999) + 1 + 1 = 2,000 times:

 

SPLS Switcher Pulse Switch SW7 Switcher Channel 7

FF2213 Find Frame 2213 LDA Laserdisk A

LS Loop Start

LS Loop Start

PLAY Play LDA Laserdisk A

W20 Wait 20 secs

RP999 Repeat Loop 999 times

RP999 Repeat Loop 999 times

 

  1. Find the TV remote (kept on the wall of the equipment room) and use it to turn on the monitor in the foyer or classroom.

 

 

 

Video Messenger

 

To add a message to the foyer monitor, continue with the following steps:

 

  1. Turn on the Macintosh computer.
  2. Double-click on the desktop icon called "Foyer Monitor."
  3. Choose "Copy" from the Edit menu.
  4. The video signal being sent to the foyer with the above script will now be copied to the Mac.
  5. Enter and edit messages using the Video Messenger keyboard.
  6. Press Play on the Video Messenger keyboard.

 

To Turn off the Macintosh when finished:

 

Note for those who always read the fine print:

The output from LDA is sent not only to the Switcher Input #7, but also through a Distribution Amplifier to the monitors in Room 102 and in the Foyer. The Video Messenger, which overlays text onto the video image from LDA, is in line between the Distribution Amplifier and the foyer monitor. So any image that is set in the Video Messenger will be seen on the foyer monitor, displayed over the image from LDA. Remember that regardless of what input is selected on the Switcher for projection in the dome, the output of LDA will still be shown on the monitors in the foyer and in room 102.

 

SVHS-Deck

 

The following commands are sent to the Sony Super-VHS deck (SVHS):

 

Make sure that the SVHS deck is set to "remote" (inspect the switch on the SVHS left front).

 

TO TURN ON AN SVHS VIDEO SEGMENT:

  1. Turn on the VP 20 minutes before.
  2. Send LN to VP.
  3. Send SPLS to SW6.
  4. Send FTIME to SVHS.
  5. Allow enough time for the SVHS deck to find the specified time.
  6. Send PLAY to SVHS.

 

The script looks something like this (assuming that the VP was warmed up):

 

SPLS

Switcher Pulse Switch

SW6

Switcher Channel 6

FTIME#

Find time (hh:mm:ss:ff)

SVHS

Super VHS deck

LN

Lamp On

VP

Video Projector

When needed......

PLAY SVHS

 

 

TO TURN OFF AN SVHS VIDEO SEGMENT:

 

  1. Send LF to VP (this keeps audio on), or change the Switcher Channel (this cuts off audio).
  2. If the audio source is the video, and not a synchronized ADAT tape, then fade out the audio with the switcher fader on the mixer.
  3. Send STOP to SVHS. This command pauses audio and video from the SVHS.
  4. If the SVHS will not be played again from this location, disengage the heads as follows:

a. Send FASTFWD or REWIND to SVHS.

b. Send STOP to SVHS.

c. Send FTIME for next location to SVHS.

 

OR, if the SVHS will not be played again during this show, the heads may be disengaged by sending REJECT to SVHS. This will eject the tape.

 

The relevant portion of a script might look like this (assuming that the audio originates from an ADAT instead of the SVHS tape):

 

LF Lamp Off VP Video Projector

STOP Stop transport SVHS Super VHS deck

FASTFWD Fast Forward SVHS Super VHS deck

STOP Stop transport SVHS Super VHS deck

FTIME# Find time (hh:mm:ss:ff) SVHS Super VHS deck

 

Macintosh Computer

 

The video projector can project the PowerMacintosh's screen (e.g., with Voyager software or PowerPoint presentation software). To view the computer through the video projector, set the switcher to the Macintosh channel with the following command:

 

SPLS Switcher Pulse Switch SW4 Switcher Channel 4

 

Handheld radio control of the PowerMac (through TrackMan Live) also affords flexible, modular operation of interactive educational shows.

 

The Macintosh can be connected to the audio rack to support audio and video editing.

 

Software on the Mac available for student use includes the following:

 
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OBU Planetarium:
http://www.okbu.edu/academics/natsci/planet/index.htm