3. The Above-slit colour filter slide and it's contents (ASCF)
   Date: 10/2/1999
   By: S.Smartt

There is an above slit colour filter slide which can be manually accessed
through a door in the A&G box. The above-slit ND slide can also be 
accessed through this door. A number of screws need undoing to get 
at them. The colour filter slide is the lower one, and the  
ND slide is the upper one. 

The colour filters are mounted like this :

          --------------------------------------------------------
 A&G Box | / / / / | BG38   | BG28   | RG630  | GG385  |  GG495  | the clear
 Door    |/ / /	/  |	    |	     |	      |	       |	 | position 
 End     |/ / / /  |(5)	    |(4)     |(3)     | (2)    |(1)	 | (0) 
          --------------------------------------------------------
           
           ------------------------> goes into A&G Box like this

The numbers refer to the position of the filter on the slide as 
called by the ICS. You should make sure that these match up to what 
is read by the ICS (using the change_agb command).  

NOTE WELL:
 YOU SHOULD NEVER MOVE FILTERS BETWEEN POSITIONS ON THIS SLIDE UNLESS
 IT IS ABSOLUTELY NECESSARY. IF YOU DO THEN YOU SHOULD INFORM THE
 INSTRUMENT SPECIALIST (STEPHEN SMARTT; sjst@ing.iac.es) IMMEDIATELY
 SO THAT A TRACK CAN BE KEPT ON WHERE THE FILTERS ARE. YOU MUST ALSO
 CHANGE THEIR POSITIONS IN THE ICS SOFTWARE, SO THAT OBSERVERS KNOW
 WHAT COMES UP ON THE MIMIC IS REALLY WHAT IS IN THE BEAM.



The Above-slit nuetral density filters go in like this 

          --------------------------------------------------------
 A&G Box | / / / / | highest|        |        |        | lowest  | the clear
 Door    |/ / /	/  |	    |	     |	      |	       |	 | position
 End     |/ / / /  |(5)	    |(4)     |(3)     | (2)    |(1)	 | (0)
          --------------------------------------------------------