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\begin{document}
\begin{titlepage}
\centerline{\huge JACOBUS KAPTEYN TELESCOPE}
\vspace{25mm}
\centerline{\Huge WIDE FIELD CAMERA }
\vspace{5mm}
\centerline{\Huge PHOTOGRAPHIC USERS' MANUAL}
\vspace{35mm}
\centerline{\large D H P Jones~~~~R W Argyle~~~~C D Pike~~~~D A Calvert}
\vspace{40mm}
\centerline{\large Version 2}
\vspace{10mm}
\centerline{\large 1991 July}
\vspace{5mm}
\end{titlepage}
\vfill
\eject
\tableofcontents
\listoffigures
\listoftables
\vfill
\eject

\section{INTRODUCTION}

   This manual is designed to introduce the observer to the
Jacobus Kapteyn Telescope (JKT 1-metre) wide field plate
camera (WFC) and to describe how the camera is used to take
plates at the f/8 focus.   Fig.1  shows the camera and its
constituent parts.   Fig.2 shows a schematic optical diagram 
of the camera.

\section{FEATURES}

\subsection{Wide Field Optics }

   The Harmer-Wynne arrangement is mounted by replacing the 
conventional f/15 Hyperboloid Secondary by a larger f/8
Spherical secondary.  In addition an afocal doublet
corrector mounted 1.47 metres in front of the f/8 focus
(i.e. in the middle of the tube)  gives a flat, 
highly corrected field of 90 arcmin diameter.   The plates used 
are 8 x 10 inches (200 x 250 mm) and the effective field has
a diameter of 1.5 degrees.   The autoguider prism and its 
support cause some vignetting which depends on the position
of the guide star.  The plate scale is 25.6 arcsec/mm (see Fig.3 )
at the centre of the field but there is some distortion
towards the edge .

\subsection{Focus}


   The telescope is focused with a
    Knife Edge assembly which carries two knife edges at 
right angles, mounted in place of the plate holder.   The
procedure is as follows; starting at the Console.
\begin{enumerate}

\item Set the Handset Setting rate to 10 arcsec/sec on the 
User Interface.   The command is HA/S 10 and then press SET
on the Console immediately below the 'Handset Buttons'; this
last action is vital.

\item Go to the telescope and remove any filters from the
 camera; open shutter with handset.

\item Insert the knife-edge assembly in the camera, and make
very sure it is seated properly.

\item Set the telescope on a star brighter than about V = 6
and as close to the observational field as possible.

\item Bring the star close to the knife edge running in the
declination direction (vertical when looking South on the Equator)
close to its intersection with the other knife edge.   Use the
handset RA motion to move the knife edge across the star
image while observing the shadow pattern by eye.   Novices
require some practice in doing this as it is necessary for the
eye to be close behind the knife edge to accept the full
light cone.   Once found you must keep your head
still or you will lose the light cone.   It pays to set the rising 
floor exactly at a comfortably height and rest your forehead
on the camera.   Unless the telescope is exactly in focus the shadow
will appear to cross the entrance pupil either in the same way
as the telescope motion or against it.

\item Adjust the secondary mirror position (FOCUS buttons on
top of handset) until the shadow pattern on the image of the 
primary is evenly occulted i.e. not selectively from one side
or the other.

\item Read and record the position of the secondary.

\item Run the focus position away from focus towards the 
opposite side that you have just come in from; then repeat

\item 

and

\begin{figure}[htb]
\vspace{8in}
\caption{The Wide Field Camera and its constituent parts}
\end{figure}
\begin{figure}[htb]
\vspace{8in}
\caption{Schematic Optical Diagram of the wide Field Camera}
\end{figure}

\item Move the star to the other knife edge but still close
to the centre of the field.

\item Take two more focus readings; one with focus readings
increasing and one decreasing.

\item Return to the console and enter the four focus positions
and their mean in the WFC adjustment book; and
include the temperature and telescope position.

\item Enter the knife edge focus into ADAM by entering KEF xxx.  
The ADAM WFC software will prompt you for filter and plate-holder
for subsequent exposures and  will adjust the focus automatically.

\end{enumerate}

The KEF is strongly correlated with tube temperature and the
observer should keep a note of \\

KEF + 0.043*(Tube Temperature)\\

which should be constant within a few hundredths of a millimetre.
 After a few observations the mean value of this function will
settle to a constant which may be used to infer the KEF from
the temperature.   Thus three or more KEF observations are
recommended for the first night of a run decreasing to one a
night from about the third night onwards 

A typical figure for the telescope focus (readouts above the 
finder eyepiece and on the information display) is 13.10 at
t = 12.deg.C for plateholder 4 and RG630 filter.

   The ultimate check on the focus is to take a focus plate;
there is an ADAM procedure to do this.   It is recommended 
that one focus plate a night be taken or whenever some
malfunction is suspected.

\subsection{Interchangeable Filters}

   A series of approximately 250 x 200 x 4 mm broad band filters
is available with holders.   They are as follows:

\medskip

\begin{table}[htb]
\begin{center}
\begin{tabular}{|c|c|c|c|} \hline

   Filter Holder &~~~   Filter ~~~  & Thickness  & ~~~   Size ~~~  \\ \hline
                 &            &    mm      &      in   \\ \hline
        1        &  UG1       &   3.8      &   9.83 x 7.86\\ \hline
        2        &  GG385     &   3.8      &   9.84 x 7.87\\ \hline
        3        &  GG395     &   3.9      &   9.84 x 7.88\\ \hline
        4        &  GG455     &   3.8      &   9.81 x 7.88\\ \hline
        5        &  GG495     &   3.9      &   9.84 x 7.89\\ \hline
        6        &  RG630     &   3.9      &   9.84 x 7.82\\ \hline
        7        &  RG715     &   3.9      &   9.80 x 7.85\\ \hline
\end{tabular}
\caption {Available broad band filters for the Wide Field Camera}
\label {Available_broad_band_filters_for_the_Wide_Field_Camera}
\end{center}
\end{table}
\medskip

All have MgF$_2$ single layer anti-reflection coatings.   The assembly is
slid into a slot in the camera and locked by a plunger about three
quarters of the way down the left-hand side.   This must be withdrawn 
to remove a filter holder.   When in place, the filters are designed 
to keep an atmosphere of N$_2$ in contact with the emulsion during an 
exposure.   (see section 2.2.4)

   In addition, two 100 x 100 x 9 mm interference filters are available.
These are:

\begin{table}[htb]
\begin{center}
\begin{tabular}{|c|c|c|c|} \hline
 Filter Holder   & ~~~Filter ~~~  &Central Wavelength &Bandwidth\\ \hline
      8          &     H$\alpha$  & 6563\AA           & 50\AA    \\ \hline
      9          &     [O III]    & 5007\AA           & 50\AA     \\ \hline
\end{tabular}
\caption {Available narrow band filters for the Wide Field Camera}
\label {Available_narrow_band_filters_for_the_Wide_Field_Camera}
\end{center}
\end{table}

\begin{figure}[htb]
\vspace{8in}
\caption{}
\end{figure}
   The effect of the converging f/8 beam was taken into account when
ordering the narrow band filters.   The above central wavelengths 
represent the effective values seen by the camera plates.   The filters
are mounted in sub-frame assemblies which in turn are fixed to the 
filter holders.   They must be inserted in one direction only as indicated
by an arrow on the vane of the sub-frame assembly.   Refocussing is 
necessary when using these filters.   Each narrow band filter has a 
smaller (25 x 25 mm) calibration filter of identical characteristics
which is available for use in the Kitt Peak calibration beam.   Three
empty sub-frame assemblies for holding 50 x 50 x 9 mm filters are 
also available.

\subsection{Plateholders}

   There are six plateholders for 250 x 200 mm plates.   The plateholders
are held in place by means of three spring-loaded clips; the seating is
defined by three legs with conical tips fitting into V-grooves.   The
back of the plateholder is removed by rotating the locking bar until
it is parallel to the long axis of the plateholder.   The plate can 
then be inserted, emulsion down, after ensuring that the dark slide
is enclosed first.   This must be done carefully as the plate has to
fit within an internal rebate.   It is best to examine a plate holder 
in the light before loading your first plate.   Each plateholder is 
also designed to be gas-tight, allowing it to maintain an atmosphere
of nitrogen for hypersensitized (baked) plates.   There are two small
nozzles near the handle allowing N$_2$ to be flushed through to remove
the existing air and hence maintain the sensitivity of the plate
during exposure.

   Squaring on of plateholders should not be necessary.   If in doubt
consult the Technical Manual (No 32 - not yet issued) or D H P Jones
for advice.

\subsection{Shutter}

   The focal plane shutter consists of a blind with a 300 x 200 mm
aperture which is mounted on two rollers.   When the camera power
is switched on the shutter will close if it has been left open
from the previous night.   When the shutter button is pressed
again, the rollers will reverse direction and the shutter opens.
Pressing the button again will activate the rollers in the
same direction and the shutter will close.   This ensures that
all parts of the plate are exposed equally.   The shortest
exposure which can be made is about 2-3 seconds.   On the
handset shutter OPEN is indicated by a RED LED and shutter
CLOSED by a GREEN LED.   The shutter can also be opened and
closed by the 3210 instrumentation computer which has a 
CAMAC interface in parallel with the handset.   This is
the normal method of observing.

\subsection{Plate Identification}

   The plate marking machine (Fig.4) is used to project 
details from the plate card (Fig 5) on to a corner of the
plate; specifically the telescope name, the running plate
number and the telescope co-ordinates.   The plateholder is
mounted on the machine in the same fashion as on the camera,
AFTER the exposure has been made at the telescope.   The timer
should be set for the emulsion being used and a table of
approximate exposures is given below.   Care should be taken to
ensure that the right time range is selected because there are
five ranges covering up to six hours; it is nearly always the
shortest.   The range is selected by the knob at the bottom right
of the timer panel.

\medskip

\begin{table}[htb]
\begin{center}
\begin{tabular}{|c|c|}\hline
            Emulsion       &    Timer Setting     \\ \hline
            IIaO          &       3 sec          \\ \hline
            IIaD          &       2              \\ \hline
            IIIaF         &       0.5            \\ \hline
            IIIaJ         &       3              \\ \hline
\end{tabular}
\caption {Exposure times for the Plate Marking Machine}
\label {Exposure_times_for_the_Plate_marking_Machine}
\end{center}
\end{table}
\medskip

These times are for hypersensitized plates; double the times
for unsensitized plates.

\begin{figure}[htb]
\vspace{8in}
\caption{The plate marking machine}
\end{figure}

\subsection{Plate numbering convention}

   This is based on the UK Schmidt Telescope Unit convention, i.e.

SINGLE LETTER prefixes denote standard plate and filter combinations:

~~~~~~~~U denotes any sensitization with UG1 filter

~~~~~~~~B denotes  O  sensitization with GG385 filter

~~~~~~~~J denotes  J  sensitization with GG395 filter

~~~~~~~~V denotes  D  sensitization with GG495 filter

~~~~~~~~R denotes F or 098 sensitization with RG630 filter

~~~~~~~~I denotes  N  sensitization with RG715 filter

TWO-LETTER prefixes denote other combinations, with the first
letter representing the short wave cutoff (i.e. the filter) and
the second letter the long wave cutoff (i.e.the emulsion
sensitization):

\begin{table}[htb]
\begin{center}
\begin{tabular}{|c|c|} \hline
   Filter:(first letter) &    Emulsion:(second letter)    \\ \hline
   U,   NO filter         &                                 \\ \hline
   B,   GG385             &    B,  O sensitization           \\ \hline
   J,   GG395             &    J,  J sensitization           \\ \hline
   V,   GG495             &    V,  D sensitization           \\ \hline
   R,   RG630             &    R, F or 098 sensitization     \\ \hline
   I,   RG715             &    I,  N sensitization           \\ \hline
\end{tabular}
\caption {Plate and filter equivalents for astronomical emulsions}
\label {Plate_and_filter_equivalents_for_astronomical_emulsions}
\end{center}
\end{table}
\medskip

Any combination not covered by the above gets an X prefix.

Examples:     J 1234        means a J plate with GG395 

~~~~~~~~~~~~~~BV 1234       means a D plate with GG385

~~~~~~~~~~~~~~UR 1234       means a red plate with no filter

~~~~~~~~~~~~~~H$\alpha$ 1234  means a plate with an H$\alpha$ interference filter

~~~~~~~~~~~~~~[OIII] 1234   means a plate with an [OIII] interference filter

\subsection{Plate and Sensitizing Card}

     These are intended to record as much detail as possible about
the plate sensitization treatment, the plate exposure and the 
quality control exercise afterwards.

   Examples of the plate and sensitizing card are given in Figs. 5 and
6.   The details of the plate card are self explanatory on the whole but 
the following points should be noted.

\begin{enumerate}

\item POSITION in the Top Left Hand corner of the plate card refers to
the TELESCOPE position during the exposure i.e. the encoder readouts.
It is this portion of the card which is projected on to the plate
itself before developing (see section 2.2.6).

\item  Details of the emulsion, batch, sensitization and box or tin
number can be obtained from the sensitizing card which is attached
to the unexposed plate tin by means of a plastic wallet.

\item  TELESCOPE POSITION refers to West or East of the pier.

\item  The records entitled DISPATCH RECORD, COPY RECORD, and
PROCESSING and PLATE GRADE should be left blank.   The 
reverse of the plate card is not for use by the observer.
\end{enumerate}

   The sensitizing card will be filled in by the officer
responsible for photographic facilities but the observer
should record the plate number corresponding to the rack
number of the tin from which the plate was taken as he
exposes each plate.   This allows a check to be made to
see if the sensitization depends on the position of the 
plate in the tin.
  
\subsection{Fiducial Marks}

   Three small red LEDs are situated in the body of the camera
just outside the working aperture.   They are designed to put three
small locating spots on the plate to indicate if there has been 
any movement during the exposure.   A short exposure is given 
at the beginning and at the end of the camera exposure .   If the images
turn out to be non-circular then the plate has moved relative to
the plateholder during the exposure.   The following table gives the 
times for which the plate marker LEDs are switched on by the WFC
software.   The exposures are made in two equal halves, one after the
beginning and one before the end of the telescope exposure.
\begin{figure}[htb]
\vspace{8in}
\caption{The plate card}
\end{figure}
\begin{figure}[htb]
\vspace{8in}
\caption{The sensitising card}
\end{figure}


\begin{table}[htb]


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Fiducial Lamp Exposure (mm.ss)
\begin{center}
\begin{tabular}{l|c|c|c|c|c|c|c|c|c|c|}
\cline{2-11}
\centering
&\multicolumn{10}{|c|}{Filter}\\ \cline{2-11}

 &1 &    2  &   3   &  4   &  5  &   6  &   7  &   8  &   9  &  10  \\ 
\cline{2-11}
              
             & UG1 &GG385&GG395&GG455&GG495&RG630&RG715&5007A&6563A& OWN \\
\cline{2-11}
               
     098    &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  \\
\cline{2-11}
               
     IIaO   &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  \\
\cline{2-11}
              
    IIaD   &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  \\
\cline{2-11}
              
    IIaE   &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  \\
\cline{2-11}
              
    IIIaJ  &32.00&32.00&32.00&32.00&32.00&32.00&64.00&98.00&  $\ast$  & 0.20\\
\cline{2-11}
              
    IIIaF  &64.00& 2.00& 2.00& 2.00& 2.00& 2.00& 4.00&  $\ast$  &  $\ast$  &  $\ast$  \\
\cline{2-11}
               
     IVN    &99.00& 8.00& 8.00& 8.00& 8.00& 8.00& 8.00&  $\ast$  &  $\ast$  &  $\ast$  \\
\cline{2-11}
\end{tabular}
\caption {Plate location marks: exposure times for various emulsions}
\label {Plate_location_marks:_exposure_times_for_various_emulsions}
\end{center}
\end{table}

\subsection{Sensitivity Calibration}

   A modified Kitt Peak Sensitometer (Schoening 1974, Fig. 7) is
used to project a 5 x 5 array of circles whose densities range
from clear to 2.28 on to the corner of the plate.   The density
of each circle for the camera calibrator is as follows:    

\medskip

\begin{table}[htb]
\begin{center}
\begin{tabular}{|c|c|c|c|c|c|c|c|c|c|} \hline
Spot No. & D & Spot No.& D & Spot No.& D & Spot No. & D & Spot No.& D\\ \hline
0   &  0.05 & 1  &  0.10  & 2 & 0.20&  3 & 0.32 & 4 & 0.39  \\ \hline
5   &  0.49 & 6  &  0.58  & 7 & 0.67&  8 & 0.69 & 9 & 0.77 \\ \hline
10  &  0.96 &11  &  1.05  &12 & 1.15& 13 & 1.25 &14 & 1.31  \\ \hline
15  &  1.44 &16  &  1.55  &17 & 1.59&  18&  1.84&19  &1.79  \\ \hline
20  &  1.96 &21  &  2.02  &22 & 2.12&  23&  2.16&24  &2.28  \\ \hline
\end{tabular}
\caption {Spot densities for the Wide Field Camera plate calibrator}
\label{ Spot_densities_for_the_Wide_Field_Camera_plate_calibrator}
\end{center}
\end{table}

\medskip
where the numbers refer to those given on the back of the
plate card (Fig.7 ).

   Again the calibration is divided equally between the 
beginning and end of the exposure by the WFC software.
An aperture wheel is provided to reduce the amount of light
passing through the calibrator.   The values given are
0.8, 1.6, 2.25, 3.2, 4.5 and 9.5 .   The wheel can also be
used to cut off the calibration source and preferably should 
be placed half way between the 0.8 and 1.6 settings to do this.
The following exposures have been found suitable for different
emulsion/filter combinations and are the ones used by the WFC
software.

\begin{table}[htb]

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Calibration Lamp Exposure (mm.ss)
\begin{center}
\begin{tabular}{l|c|c|c|c|c|c|c|c|c|c|}  \cline{2-11}
&\multicolumn{10}{|c|}{Filters} \\ \cline{2-11}
        &    1  &   2  &   3  &  4 & 5  & 6  & 7 &  8 &  9  &  10 \\ 
\cline{2-11}
        &   UG1 &GG385&GG395&GG455&GG495&RG630&RG715&5007A&6563A& OWN \\
\cline{2-11}
               
  098    &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  \\
\cline{2-11}
               
  IIaO   &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$   \\
\cline{2-11}
              
  IIaD   &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$   \\
\cline{2-11}
              
  IIaE   &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  &  $\ast$  \\
\cline{2-11}
              
  IIIaJ  &16.00& 8.00& 8.00&16.00&32.00&64.00&99.00&  $\ast$  &  $\ast$  & 0.30\\
\cline{2-11}
              
  IIIaF  &32.00& 2.00& 2.00& 2.00& 4.00& 1.00& 8.00&  $\ast$  &  $\ast$  &  $\ast$  \\
\cline{2-11}
               
  IVN    &64.00&16.00&16.00&16.00&16.00&16.00&16.00&  $\ast$  &  $\ast$  &  $\ast$  \\
\cline{2-11}
\end{tabular} 
\caption {Plate calibration exposure time for various emulsions}
\label {Plate_calibration_exposure_time_for_various_emulsions}
\end{center}
\end{table}
\begin{figure}
\vspace{8in}
\caption{The Kitt Peak Sensitometer}
\end{figure}

\medskip

   For more details contact D H P Jones.

\subsection{Visual Guiding}

   A guiding eyepiece is mounted on a goose-neck which views a part
of the field; it has a field of about 1 arc min. and is equipped
with double crosswires with red illumination which can be varied
with the circular potentiometer on the camera body.   In principle
a guide star could be found by sweeping across the field with the
guider probe but this would be very laborious.   It is much better
to compute the probe co-ordinates of a suitable guide star in advance
(see section 6.2.2 ).   The telescope can be guided visually using
the handset but is normally guided automatically with the 
autoguider.   There is a prism  which can selectively direct
the light either into the autoguider or the eyepiece.   The eyepiece
is usually confined to making SNAFUs; therafter the autoguider can
be used unaided until another SNAFU is necessary.
                                             
\subsection{Auto-Guiding}

   An FW 130 image dissector photomultiplier (with S20 response) is
used for autoguiding.   The tube is housed in a cylindrical body which
can be moved longitudinally to make it parfocal with the plateholders.
This adjustment is rarely needed and is always done by the 
LPO staff.   The head amplifier and EHT unit are carried
in the telescope electronic rack;  a photodiode protects the system
by closing down the EHT whenever it detects excessive light.

   Two rotatable filter wheels compensate for guide
stars of differing brightness or colour.   Details of the filters 
are:

\begin{table}[htb]
\begin{center}
\begin{tabular}{|c|c|c|} \hline
 ~~~Filter~~~      &     Colour     &   Neutral Density       \\ \hline
            1         &     Clear      &      Clear            \\ \hline
            2         &     U (UG1)    &       0.5             \\ \hline
            3         &     J (Wratten 28) &   1.0             \\ \hline
            4         &     F (RG630)  &       2.0             \\ \hline
\end{tabular}
\caption {Available filters for the Wide Field Camera Autoguider}
\label {Available_filters_for_the_Wide_Field_Camera_Autoguider}
\end{center}
\end{table}

   A display at the console shows the error signals from the autoguider
which are fed to the 3210 drive program.   See section ??2.1.2?? for
details of operation.

\subsection{Polaroid Camera}
 
   A 4 x 5 inch Polaroid film back can be mounted on a special bracket
8 cm behind the plane of the knife edge assembly.   This records
Foucaultgrams and assists in telescope focusing tests.   The film
back is hinged to allow visual inspection or it may be removed
altogether.

\subsection{Handsets}

\begin{itemize}

\item Camera handset controls

\begin{enumerate}

 \item Shutter (open = red LED, closed = green LED)

\item Calibration Lamp (Illuminated when calibration lamp off)

\item Fiducial lamps   (Illuminated when fiducial lamps off)
\end{enumerate}
\end{itemize}


\begin{itemize}

\item  Telescope handset controls

\begin{enumerate}

\item Focus (+/$-$) on top of the handset

\item RA (+/$-$) on the face of the handset

\item Dec(+/$-$) on the face of the handset both mimic the
 console buttons for SET, GUIDE and INCREMENT and have rates or increments 
as set by the User-Interface
\end{enumerate}
\end{itemize}

\subsection{Scout Eyepiece}

   This is a Plo\"ssl eyepiece of 50 mm focal length giving a magnification
of x 160.   It is mounted on a plateholder base relative to which it
can move in $r$ and $\theta$ to cover the whole 90 arc minute diameter field.
Its field of view is 15 arc min.

\subsection{Meteorological Sensors}

   The positions of the temperature sensors on the telescope tube are:-

\begin{enumerate}

\item  Just above the mirror cell on the Serrurier truss
\item At the top end ring
\item At three points around the top surface of the primary mirror
spaced 120 degrees apart.
\end{enumerate}

   There are three temperature/humidity sensors which can be read 
from the console mounted respectively, inside the control room,
 inside the dome and outside the dome in a Stevenson screen.
 The control room should be maintained at 20 deg.C and 50 per cent
 humidity by the air conditioning.   Any divergence from these values
 can damage the computers so call the duty technician if such occurs.
   Dew is prone to form on the 
optics and steelwork of the telescope at humidities above 90 per
cent so observers must close down when this limit is reached.

   The wind speed is measured by an anemometer on a mast to the SE
of the building.  The dome must be closed for wind speeds
 in excess of 50 km/h.   Observers are asked to record the weather 
on the night report form.

\subsection{Operation Under ADAM}

  This is more fully described in section 3.2
\vfill
\eject

\section{PREPARING THE TELESCOPE FOR OBSERVING}

\subsection{Dry Dark Room (SW corner of observing floor)}

   This room should contain the plate marking machine, an empty tin to
receive the exposed plates and a pair of cotton gloves to wear while
handling plates.   Your current supply of plates should be kept in
the refigerator in the hall during the day and brought up to the
dry dark room about two hours before observing to allow them to
 warm up to working temperature.   Ensure an adequate supply of
 plate cards at the console.   It is best to have two working
plate-holders in the dry darkroom (preferably numbers three and four) and
keep the knife-edge and the box of filters on the rising floor.
Two is the minimum number of plateholders for efficient operation;
one to expose and one to reload.   If you try to use more you will
tangle yourself up in logistic complications.
The scout eyepiece is only needed for your first SNAFU, for emergencies
and for showing the Moon \footnote{If you have to 
show the Moon to tourists don't use the Astronomical Almanac because
you will be chagrined to find yourself miles off because of parallax.
Use the program MOON on the 3210 (account 60) which gives the 
topocentric position for mean equinox of date.   Even better prepare
yourself by running the program [DHPJ.SOLSYS]LUNA on the VAX 8300
which is the same program but with more glamorous cosmetics.} to tourists.  
It is best kept in a drawer in the dry dark room out of harm's way.  

\subsection{SNAFU}

   Set on a bright star and SNAFU, first coarsely using the Scout eyepiece
and centering the star by eye.   Then set the guide probe co-ordinates to
x = 143.1, y = 100.1 and do a more careful SNAFU on the crosswires.   If you
are familiar with the INPSCF it pays to write
down the coefficients PCIH and PCID.   These values can be re-entered
on subsequent nights thus obviating the need for further SNAFUs.

\subsection{Knife edge focus}

  Knife edge for focus following section 2.2.2 about once a
night.

\subsection{Instrumentation Computer}

   Signon to 3210 Instrumentation Computer

         SI(GNON) XYZT,n,n   where XYZT are the observer's initials and
n = 1....8 but keep to one number for the whole of your run.

         ADAM

         Select f/8 (=2) and WFC (=8)

\subsection{Open Dome}

   If the weather is set fair then open the dome at the time (~1800)
when inner temperature = outer temperature and adopt a compromise
azimuth for the dome which is away from the setting Sun but into the
wind.   The more nearly equal the inner and outer temperatures are
during the night the better your seeing will be.   It pays to check
the whole building and turn off all unnecessary lights and heaters
(except those in the dark-room!).

\vfill
\eject

\section{OBSERVING}

   Having started the telescope following the directions in the 'JKT
User Guide' and carried out the operations listed in section 2, you
are ready to expose a plate.

\begin{enumerate}

\item While at the console point the telescope towards the zenith
and select the object to observe.   Enter its position into the 
User Interface and start making out a plate card, including
emulsion, filter and autoguider x,y.

\item Carry the card with you to the dry dark-room, turn out
the lights and load a plate-holder with the appropriate plate and
mark its sensitization history on the card.

\item Climb the steel ladder to the rising floor carrying the plate
holder and plate card.   Load the camera with the appropriate 
filter having carefully cleaned it with optical tissue.   Set the
autoguider x,y to the values on the card and clamp the screws.
Check the calibration lamp aperture.   Load the plate-holder into
the camera and check that the LED on the camera handset shines
GREEN for shutter closed and that both lamp buttons are
illuminated, implying both Calibration and Fiducial lamps
are extinguished.   Release the locking plunger and withdraw the
dark slide.   Creep back to the console using your torch as little
as possible.

\item At the User Interface type:

UI$>$ NEXT  (source-name)

UI$>$GO

and check that the Dome is not set to 'Manual'.

\item When the telescope comes to rest switch on the autoguider
and press FIELD.   You will see the small upper square brighten
from the left and filling in four seconds to reveal a star
somewhere near the middle.   If there isn't an obvious star there
then you may have done something wrong so go back and
check everything.  If you still don't see the guide star then
perform a square search until it appears.  Press ACQUIRE and you
 will see the star move
to the middle of the small square whereupon a small circle will
appear in the lower half of the screen.   A cross representing the
star will step towards the circle and as soon as it lands inside 
you will get a new display consisting of two bell-shaped curves
which are the x,y sections of the star image and the message
OK TO GUIDE?   Check that neither profile is noticeably double
peaked indicative of a double star or excessively noisy,
meaning that the guide star is too faint.   If the guide star is too bright
then the middle of the profile will be cut by numerical overflow.
Select a neutral density filter for the autoguider which gives
a smooth profile.   If you are happy with the guide star you
have acquired press GUIDE and you will see a display with a 
larger (2 arc sec) circle with a cross representing the star
stepping about inside (or not very outside) it.   You then
close the autoguider loop with the green button, miles away
from the other autoguider buttons at the right hand side of the
middle console bay.   You should see the autoguider pull the
cross towards the centre of the circle and hold it within the
circle for about 90 per cent. of the time.

\item When the autoguider is running nicely turn to the 
instrument computer screen and type:

~~~~~~~~~~       SETUP   answer questions giving details of plate

~~~~~~~~~~       AGSETUP answer questions giving details of autoguider

~~~~~~~~~~       FOR     exposure time mm.ss

~~~~~~~~~~       EXPOSE  which carries out all the operations necessary to

~~~~~~~~~~~       start an exposure.   


\item Fill in as many details on the plate card as you can and enter
the plate into the PC log.   You now have free time on your hands to watch
the autoguider in action.   The autoguider should be doing its
best to hold the star in the circle.   Watch the RT value (Relative
Transmission) which should stay within the range 3. to 0.3 unless
it is quite cloudy.   If the relative transmission drops below
about 0.1 the autoguider will cease to guide and the message CLOUDY
will appear above RT.   The telsecope will continue to free-wheel 
which it does quite well and no great harm is done because little
light is reaching the plate.   When the cloud thins the autoguider
will happily pick up the star again and carry on.   However on rare 
occasions the autoguider may go berserk and give RT ~100. or
even a negative number.   If this happens type ABORT immediately
on the instrument computer or your plate will be ruined.

   After watching the autoguider for a while you will conclude
that it is not much more interesting than watching television.
This is the time to unload the plateholder of the previous plate
and to get prepared for your next plate.   If the exposure is 
longer than about half an hour you can go downstairs and develope
such exposed plates as you have accumulated.   If you are
feeling hungry you can go downstairs and eat your sandwiches but
don't eat them in the control room.

\item Half way through the exposure the instrument computer will
display the cheerful message:\\

   Cheer up, you are half way through!\\

\item At the end you will get some house-keeping messages about the
calibration and fiducial lamps, followed by the message that
the shutter is closed.   Send the telescope to 'Zenith Park'
with the button immediately below the user-interface.

\item   Pick up the plate card for your next
plate and take the already loaded plate-holder from the dry
dark room to the observing floor.   Remove the old plate from the
telescope and mount the new one following the procedure in 
Section 4.   Carry on with the new plate until it is exposing
and then return to the dry dark room to unload the previous
plate.

\item Mount the plate-holder in the plate marking machine
(Fig.4) and insert the plate card face down so that the
plate number is opposite the window.   Set the timer to the 
time for the appropriate emulsion.   Turn out the lights,
release the plunger and withdraw the dark slide.  Toggle the
switch and the plate number will be transfered to the 
plate.   Close the dark slide and remove the plate-holder
from the machine.   Open the plateholder and wearing cotton
gloves put the plate in to a rack in the tin for exposed
plates.   For even development the best arrangement of the 
plates is:

\centerline { 6gggggggggggggggggggggggggggggggggggggggggggggggggg6}

\centerline {  eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee}

\centerline { 5~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~5}

\centerline { 4eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee4 }

\centerline { ~gggggggggggggggggggggggggggggggggggggggggggggggggg~}

\centerline { 3gggggggggggggggggggggggggggggggggggggggggggggggggg3}

\centerline {  eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee}

\centerline { 2~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~2}

\centerline { 1eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee1}

\centerline {  ~gggggggggggggggggggggggggggggggggggggggggggggggggg}
        

where e and g represent the emulsion and glass sides of the
plate.   While the racks can hold six plates it is best not
to develope more than four together for fear of non-uniform 
development.
Put the plate card next to the tin and take it downstairs
when the whole tin goes down for development(section 4).
\end{enumerate}
\vfill
\eject

\subsection{WFC ADAM Software}

   The WFC software has control over the hardware mechanisms --
the shutter (open/close), the calibration lamp (on/off) and the
fiducial lamp (on/off).   The shutter status can be read directly
from CAMAC but the lamp status cannot.   The lamps can only be
commanded to change states.   For this reason ADAM assumes that
on starting both lamps are off and prompts the user to check 
that this is true.   Thereafter the software attempts to 
keep a check of status changes internally but commands are
available to force a realignment of the real and perceived
status following any mishap.   The roller blind shutter should
not be used for exposures of less than one second although the
times of issuing the open and close commands are recorded to
millisecond accuracy and correspond to the 'real' shutter
open/close time within a hundred milliseconds.   The handset
buttons 'Calibration' and 'Fiducial' are illuminated irrespective
of what commands have been sent by CAMAC and whether the lamps
are shining or not.   It is only when switching the lamps on/off
via the handset that the buttons do/do not light up.   However
the LEDs (GREEN for Closed and RED for Open) are correct whether 
the shutter has been operated either from the handset or from
CAMAC.

   The telescope focus and lamp exposure times all vary depending
on the plate-holder/filter/emulsion combination.   The known
values are kept in a look-up table which is accessible through
the command CHANGE.   Sample screen outputs from CHANGE are given
in Appendix A.   Since the plate-holder number and the filter/
emulsion names are kept as ADAM variables the software can look
up the appropriate focus offsets and exposure times, as and when 
it requires them.   This is normally done as part of the 
exposure control procedure but can be done separately with 
low-level commands.   The usual procedure is to turn on the
lamps for half the specified exposure immediately after the
shutter has been opened and to add the other half just
before the shutter closes.   If the specified exposure
time is less than the nominal lamp exposures then the observer
is prompted to decide on alternative strategies.

   Although the WFC cannot produce data files as such, dummy
files with full descriptor packets are created in order to
document the plates.   The formation of these files is 
normally handled automatically within the exposure control
procedure.   The procedure for writing descriptors can be run 
separately but it will overwrite all existing information and
should be used with care.   The information needed for this 
documentation is retrieved from ADAM, the WFC D-task or the
telescope control procedure as appropriate.   Any information
which must be supplied by the observer is prompted for
when the procedures SETUP and AGSETUP are run.   However any
of the parameters set in SETUP may be specified individually
as well as and when they change.

   Exposures are controlled by specifying a start time (AT) and an
exposure length (FOR) and are then started by the EXPOSE(WFC) command.
It is also possible to control the separate functions e.g.
shutter operation, status of lamps, packet-writing individually
if need be.   When using the EXPOSE(WFC) command, exposures can
be paused and continued at will.   Start and stop times of the
first five pauses will be recorded in the descriptor
information.   Further pauses are allowed for but will not
be documented.   Details of individual commands are given
below.   The parts of commands in parentheses are optional
for on-line entry but the full commands must be used in a 
procedure.
\vfill
\eject
{\bf Initialization}

\begin{tabular}{ll}
                   &\\
     WFCINIT       & will reload and initialize all WFC software\\
                   &\\
{\bf Focus offsets/ Lamp Exposure Times}
                   &\\
                   &\\
     CHANGE        & load/edit the look-up table of focus offsets\\
                   & and exposure times.   The offsets are in \\
                   & millimetres (-9.99 $\leq$ offset $\leq$ 99.99; enter\\
                   & -9.99 to indicate an unknown value).\\
                   & The times are in mm.ss format i.e. \\
                   & 3.2 = 3 minutes 20 seconds.   When running\\
                   & CHANGE (which is run automatically at\\
                   & startup) a null response will pass on to the\\
                   & next parameter, while entering E(ND)\\
                   & will quit the program altogether.\\
                   &\\
    LC(HANGE)      & produces a hardcopy of the lookup-tables by \\
                   & the simple expedient of running CHANGE\\
                   & in 'auto' mode and then printing the\\
                   & relevant part of the ADAM logfile.\\
                   &\\
    KEF xxx        & sets the current knife edge focus value \\
                   & to xxx.   This is also run within the \\
                   & general SETUP procedure.   The telescope\\
                   & focus that will be set before an exposure\\
                   & starts is:\\
                   &     (KEF + plateholder offset + filter offset)\\
                   &\\
    WFCFOCUS       & will pick up the knife-edge focus, the \\
                   & plateholder and focus offsets and set the\\
                   & telescope focus accordingly.   Normally run as\\
                   & part of the exposure control procedure. \\
                   &\\
    GETPHFIL       & reads the look-up table and sets the \\
                   & appropriate ADAM variable with the values of the \\
                   & plateholder and focus offsets.   Normally run \\
                   & within the exposure control procedure.\\
                   &\\
    GETCFEXP~~~~~~~       & read the look-up table and load ADAM variables\\
                   & with the appropriate calibration and fiducial\\
                   & lamp exposure times.   Normally run as part of\\
                   & the exposure control procedure.\\
                   &\\
                   & Note that the last two commands do require that\\
                   & a valid plateholder number, filter and emulsion\\
                   & name have previously been specified.\\
                   &\\
\end{tabular}
\vfill
\eject

\begin{tabular}{ll}

{\bf Information Setup}  &\\
                   &\\
    SETUP          & steps through and requests all the information\\
                   & that is needed to control an exposure and to\\
                   & document it fully.   (Not including the start\\
                   & and exposure times.\\
                   &\\
    AGSETUP        & gathers information for the autoguider documentation.\\
                   &\\
    QSETUP         & produces a terminal listing of all SETUP parameters.\\
                   &\\
\end{tabular}

{\bf Lower level routines allowing variables to be set individually are:}

\begin{tabular}{ll}

                   &\\
HYPER*~~~~~~~~~~~~~~         & details (up to forty characters) of \\
                   & hypersensitisation (if any) of the emulsion.\\
                   &\\
EMULSION*      & emulsion name (upper/lower case accepted).\\
                   &\\
FILTER*        & Filter Name\\
                   &\\
FIELD*        & Field or Object Name\\
                   &\\
    PH(OLDER)      & Plateholder serial number\\
                   &\\
    DIFFRA         & differential track rates( in secs/sec and arcsec/sec\\
    DIFFDEC        & in use during the exposure.   These are not as yet\\
                   & available over the IPL, and are not included in\\
                   & the global setup procedure.\\
&\\
    NEWPLATE       & sets the number of the next plate to be used\\
                   & and hence the run number of the next 'data'\\
                   & file to be created.   It is normally \\
                   & incremented at the end of the exposure\\
                   & control procedure.   The ADAM variable which\\
                   & is actually set is called NEXTPLATE.\\
                   &\\
    CLA            & set the calibration lamp aperture\\
                   &\\
    DOMET(EMP)     & record the temperature during the exposure.\\
                   &\\
    RHUMID         & record the dome relative humidity during the\\
                   & exposure.\\
                   &\\
\end{tabular}

*The first four commands (marked with an asterisk) require
character variables as input.   Thus if the response contains
delimiters it must be contained in quotes; e.g.\\

          HYPER "Boiled in Rioja for 2 hours"\\

If the command line in any of the above procedures is zero
(numerical input) or blank (character input) the parameter
will be prompted for in which case quotes will not be
required for the character input (this is the case when 
running as part of the general SETUP procedure).   If any
of the above commands are required in user-defined
procedures and a prompt for the input is desired then
use a zero or a blank command line parameter e.g.

~~~~~~~~PROCEDURE MYSETUP
   
~~~~~~~~KEF 0 ; FILTER " " ; EMULSION " "
   
~~~~~~~~END PROCEDURE

will ensure that all three pieces of information will be
prompted for.

{\bf Data File Descriptors}

   After each exposure a dummy data file is allocated and packet
descriptors are written to it.   Two packets are included at 
present; the observation packet which is instrument independent
and the WFC detector packet.   The packets are normally written
at the end of an exposure from within the control procedure but
can be written independently using :-
\medskip

\begin{tabular}{ll}
   PUTDESC(RIPTORS) n  & writes descriptors to EXISTING file.\\
                       & If n=0 descriptors will be written to\\
                       & R(NEXTPLATE) otherwise to R(n).\\
                       & Note that this routine clears all existing\\
                       & descriptors so do not re-use it after\\
                       & having used COMMENT on a file.\\
                       &\\
   COM(MENT)        n  & will add comments to a data file as extra\\
                       & descriptors.   If n=0 they will be added to\\
                       & the last completed exposure file\\
                       & (i.e. R(NEXTPLATE - 1));  otherwise to \\
                       & R(n) - which must already exist.   Each line\\
                       & of comment can be up to 40 characters.   \\
                       & Because the file must already exist and\\
                       & because PUTDESC overwrites descriptors you cannot\\
                       & use COMMENT to add comments to the current plate\\
                       & file DURING the exposure but must wait until it\\
                       & has finished.\\
                       &\\
                       &\\
\end{tabular}

{\bf Specification and Control of an exposure}

\medskip

\begin{tabular}{ll}

   AT hhmmss~~~~~~~~~~~~~~~ & specify the start time (UT in hhmmss format).\\
                       & A value of 0 means start as soon as possible;\\
                       & otherwise the shutter will not open until the\\
                       & specified time (accurate to ~0.1 secs).   The\\
                       & parameter value is retained until explicitly\\
                       & changed and so does not need to be set for\\
                       & each exposure.\\
                       &\\
                       &\\
   FOR  mm.ss          & specify the required exposure time in mm.ss\\
                       & format( i.e. 3.20 = 3 minutes 20 seconds).\\
                       & Exposures greater than 30 seconds (0.30) will\\
                       & be streamed as background processes.   The\\
                       & value is retained until changed and has an\\
                       & upper limit of 300.0  .\\
                       &\\
\end{tabular}
\vfill
\eject
\begin{tabular}{ll}
   EXPO(SEWFC)~~~~~~~~~~         & collects all the information necessary to \\
                       & control the exposure, sets the telescope\\
                       & focus, switches lamps on and off as necessary\\
                       & and opens the shutter for the requested \\
                       & time; writes descriptors to dummy data file\\
                       & at end.\\
                       &\\
   PAUSE               & closes the shutter.   The start time for up to\\
                       & five pauses is recorded in the descriptor \\
                       & information.\\
                       &\\
   CONTINUE            & open the shutter.   The time is recorded as for\\
                       & PAUSE.   The exposure time recorded in the \\
                       & descriptors makes due allowance for any pauses\\
                       & during the exposure.\\
                       &\\
\end{tabular}

There are several lower level commands relevant to exposure control.
 
These are:-     

\begin{tabular}{ll}
                       &\\
   OPEN                & open the shutter and leave it open.\\
                       &\\
   OPENFOR  mm.ss~~~~~~      & open the shutter, wait for mm.ss and then close it.\\
                       &\\
   CLOSE               & close the shutter.\\
                       &\\
   CALON )             &\\
   CALOFF)             & switch on/off the calibration/fiducial lamps.\\
   FIDON )             &\\
   FIDOFF)             &\\
                       &\\
   CALFOR    mm.ss )   & turn the calibration/fiducial lamps on for the \\
   FIDFOR    mm.ss )   & specified time.\\
                       &\\
\end{tabular}

{\bf Information}

A number of commands are provided to establish the state of play:-

\begin{tabular}{ll}

                       &\\
   QSETUP~~~~~~~~~~~~~~~~~~~   & produces a list on the terminal of the SETUP\\
                       & parameters supplied by the observer.\\
                       &\\
   ?ALL                & reports the status of the shutter, lamps and \\
                       & exposure (if in progress).\\
                       &\\
\end{tabular}
\vfill
\eject
\begin{tabular}{ll}
   ?FIDUCIAL           & reports status of fiducial lamp.\\
                       &\\
   ?CAL(IB)~~~~~~~~~~~~~~~~       & reports status of calibration lamp\\
                       &\\
   ?SH(UTTER)          & reports status of shutter\\
                       &\\
   ?TOGO               & if an exposure is in progress it will tell you how\\
                       & much time remains\\
                       &\\
   ?EXP                & reports the exposure times that are currently set\\
                       & for the lamps and shutter\\
                       &\\
\end{tabular}

   As mentioned earlier there is no HARDWARE manner for ADAM to know the
status of the lamps.   If the true status (as defined by eye) gets out of
step with the ADAM status (usually as a result of an exposure failing or
some other software error) then a realignment can be forced by the 
following procedures:-

\begin{tabular}{ll}
                       &\\
    CALISON   )        &\\
    CALISOFF  )~~~~~   & force ADAM to think that the fiducial/calibration\\
    FIDISON   )        & lamps are on/off.\\
    FIDISOFF  )        &\\
                       &\\
                       &\\
\end{tabular}

{\bf Focus Runs          }

\medskip

   A clone of the CCD focus procedure is provided.   It runs with the 
command:

\begin{tabular}{ll}
                       &\\
    FOCUS              &  performs a complete focus run.   The number of\\
                       &  exposures, the exposure time and the telescope\\
                       &  step direction will be prompted for.   Exposure\\
                       &  times are specified in SECONDS and should be{<60.}\\
                       &  A double telescope step is made before the last\\
                       &  exposure.\\
                       &\\
{\bf Associated commands are:}&\\
                       &\\
    STEPSIZE  xxx      &  sets the telescope step size (used in FOCUS) to\\
                       &  xxx arcseconds.   Default = 20.\\
                       &\\
    FOCINC    xxx      &  sets the focus increment (used in FOCUS) to xxx\\
                       &  mm.   Must only be specified to TWO decimal places,\\
                       &  no more.\\
                       &\\
    SETFOCUS  xxx      &  sets the telescope focus to value xxx by a \\
                       &  message sent on the IPL (inter-processor link\\
                       &  between the PE 3210 (ICS) and the PE 3220 (TCS))\\
                       &\\

\end{tabular}
\vfill
\eject

\section{PLATE PROCESSING}

\subsection{Introduction}

   There are three dark-rooms in the JKT dome.  First is the
dry dark-room at the SW corner of the observing floor.  Second is the 
chemical and mixing room off the hall on the office floor and next
 to it and third is the plate processing 
darkroom.   Fig. 8 shows the layout of these rooms.
Adequate amounts of chemicals in the recommended concentrations
will be prepared for all observing runs with the
Wide Field Camera and Richardson Brearley spectrograph.
Check with your support astronomer that this will be done
shortly before your run.   Fig 9 shows the layout of the
plate processing plant.   The four tanks (DEV - F2) are immersed
in a bath of water which is maintained at 20 deg.C by means
of a Churchill circulator.   It takes about two hours for
fresh tap water (at 7 deg.C) to be heated to the necessary 
temperature and a little longer for the chemicals in the tanks
to reach 20 deg.   In most cases Kodak chemicals and emulsions
are used.   The procedure is as follows:
\begin{figure}
\vspace{8in}
\caption{A ground plan of the JKT Photographic Suite}
\end{figure}
\subsection{Preparation before observing}

\begin{enumerate}

\item Check that the darkrooms are adequately warm (at least 18 deg.C)
and that the bath temperature is 20 deg.C.   The temperature of the 
darkroom can be adjusted empirically by adjusting the controls
on the two wall heaters.   The indicator on the Churchill should be set
to about 22 deg.C to allow for losses in the tubing when the bath
water is being pumped around.

\item Start the Elga de-ionizing plant from the button on the far wall
beneath the water pressure gauges.   Full details of the Elga are
given in an appendix.    The valve is set so that the water does
not overflow the outer tank in the water bath, and should not need
adjusting.

\item The nitrogen is supplied from the site network.
Set up the
length of the nitrogen bubble burst required and the interval
between bursts.   The recommended times are 3 secs and twenty secs.
which are marked against the controls.
The switches marked V1 controls the Nitrogen to the developer
and stop-bath tanks and V2 the two fixer tanks.
The flow can be controlled independently in each tank using the
yellow-handled valves.    Turn off the Nitrogen to each tank when
you have finished with it.

\end{enumerate}

\begin{figure}
\vspace{8in}
\caption{The layout of the Plate Processing Plant}
\end{figure}

\subsection{Preparation before developing}

\begin{enumerate}

\item  Fill the wash tanks W1 and W2 and allow a continuous flow
of water through them.   This must be slow, especially in winter
to allow the wash to reach the 20 deg.C temperature of the 
processing bath.   If it is too slow you won't wash all the
impurities out of the emulsion and if its too fast you risk
reticulating the emulsion through thermal shock in the
cold water.

\item  Set the clock timer to five minutes by turning the hands
on the clock face to this value with the knurled head in the
middle.   Controls on the side of the clock allow a buzzer
to be activated at the end of the exposure if required and also
to run in the increasing direction instead of decreasing.
The clock is started by pressing the button on the top
left of the body and on the top right.   To prevent the
luminous dial fogging the plates its face has been covered
except for the first quadrant (15 minutes or seconds).

\item Switch off all safelights and ensure that all indicator
lights on the Churchill cooler and other equipment are
adequately shielded.

\item Check that the 25x20 cm WFC plates have been identified
in one corner by using the plate marker in the following 
manner.

\begin{enumerate}

\item Insert the plate card so that the corner showing
the plate number is over the hole in the plate and then
close the flap.

\item  Set the timer to about two seconds and ensure that the
range is on its lowest value. The exact value depends on the
emulsion and is given in Table...

\item  Place the plateholder on the right hand part of the
plate marker

\item Pull the plate-holder dark slide

\item Toggle the switch.

\item Replace the dark slides and remove the plateholder

\end{enumerate}

\end{enumerate}

\subsection{Processing Plates from the Wide Field Camera}

\begin{enumerate}

\item Start the nitrogen bubble burst in the developing
tank.   Remove the plate rack from the exposed plates tin
and quickly place in the developing tank to coincide as
closely as possible with a nitrogen burst.

\item Start the clock.   The development time for Kodak
emulsions is five minutes at 20 deg.C in D-19 developer; see Fig 10
for development times at different temperatures.

\item  At the end of five minutes, take the plate rack out
of the tank and allow the excess developer to drip back
in to the tank for 15 seconds.

\item  Start the nitrogen burst in the stop-bath tank
and immerse the plate rack in it for 1 m 45 secs.
Close the valve on the development tank while this is 
happening.

\item Remove the tank from the stop-bath and hold it 
over the tank for 15 seconds to drain
  
\item Start the Nitrogen burst in tank F1 (first fixer)
and immerse the plate rack for two minutes (KODAK III
emulsions) or four minutes (KODAK II emulsions).   Close the
valve on the stop-bath tank.

\item  Reset the clock for the required period, start the
Nitrogen in tank F2 and immerse the plate rack in this tank 
for the same time as Fix 1.  At this stage a red safelight (ISO906)
may be used on 'blue' emulsions i.e. IIaO, IIIaJ to check
that the plates have cleared.   At the end of the period,
the white light above the processor may be switched on.
Check that all Nitrogen bubble burst valves have been 
switched off.

\item  Remove the plate rack from F2, allowing excess
fixer to drip back into the tank and immerse it in the 
 wash, W1 and open the tap so that there is a perceptible
trickle of running water.   At the same
time start the elga de-ionising plant running.

\item After 30 mins transfer the plates to the de-ionised 
wash.   The lower meter will drop to zero after about
ten seconds and will then slowly increase.   When it
reachs 1. remove the plates from the de-ionized tank.

\item  Remove the plate rack and allow it to
drain before placing it in the Slee plate drier.
Transfer the plates into one of the 
plastic racks and allow to dry.   This usually takes an hour
or more.   Don't use the fans in the plate-drier.

\end{enumerate}

     At least once a week the water bath for the tank line
should be drained and refilled.   The drain cock is
a red valve beneath the sink.

\subsection{Development in the plate-rocker tank.}

\begin{enumerate}

\item  Plug the plate-rocker into its dark-room clock and the
dark-room clock into the mains.   Place the footswitch on the
floor.   Set the speed to 5.5 on the scale.

\item Lay out two photographic dishes about one-metre square
on the sinks to the left of the tank line.   In the left hand
one put 4-litres of Kodak indicator stop bath.   Into the
right put four litres of working strength Ilford Hypam fixer.

\item Pour 1200 mlitres of D-19 developer into the Rocker-
Tank and ensure that the lid and a developing rack are
conveniently to hand.

\item If the room temperature is 20 deg C set the clock to
5 min 15 sec; the 5 min is for development and the 15 sec
for handling.   If the temperature is not 20 deg C adjust the
5 min accordingly.   Push the left hand `start' button the
clock.   This will have no immediate effect.   Put a 
cardboard box in front of the clock because it is bright
enough to fog a plate.

\item In darkness transfer a plate from the storage tin to
the developing rack and clip it in emulsion up.   Do
this with great care or you will chip or even break the
plate.   Securely
replace the lid of the tin.   Push the developing rack
a few centimetres down into the rocker tank.

\item Start the rocker tank with the foot-switch and follow the 
rotation of the tank with your hands on the developing rack
handles.   As you feel it dip to maximum inclination firmly
push the developing rack all the way down.   As the tank
returns to the horizontal it will send a uniform wave smoothly
over the emulsion.   Place the lid on the rocker tank.

\item Towards the end of the development time watch the clock
until there is only fifteen seconds to go.   Remove the
rocker tank lid and locate the handles of the developing rack.
When the tank stops promptly remove the rack from the tank and raise
it near to the vertical so that all excess developer drains
back in to the tank.  The object is to stop development quickly
and uniformly.

\item Transfer the rack to the stop bath.   Insert the developer
rack into the stop bath and promptly raise one side out again to
an angle of about 15 degrees.   Then reverse the process so that
the other side of the rack is free of the stop bath.  Repeat this
process at approximately one second intervals for thirty
seconds.   The objective is to get smooth waves of fresh stop
bath running over the emulsion and stopping the development
uniformly.

\item After the violent stage of the stop bath leave the plate
a further 90 seconds there as timed by the clock over the 
tank line.   Gentle agitation is sufficient at this stage.

\item Remove the plate rack from the stop-bath and allow all
excess fluid to drain back.   Transfer to the fixer dish
and agitate gently for two minutes (Kodak III emulsions)
or four minutes (Kodak II emulsions) as timed by the clock.

\item At the end of the first fix switch on the red safe
light at the top left of the tank line.  Don't worry if the
plate looks black; they always do at this stage.   Unclip
the plate from the developing rack and place it in a 
stainless steel rack from the bubble-burst line and place
both in Fix 1 of the bubble burst line.

\item Put the now empty developing rack in the sink at the
right hand end of the bubble-burst line.   There are three
developing racks and it is usual to develope three plates
one after another in the rocker tank.   After three the
developer is discarded.

\item Develope the next two plates in exactly the same way
and store them in Fix 1.   Then transfer them to Fix 2 and
give them two minutes bubble burst (III emulsions) or
four minutes (II emulsions).   Complete the processing as
for the bubble burst line.

\item Pour the developer away and wash up the tank and three
racks.   Leave them to drain ready for the next campaign.   

\end{enumerate}

\begin{figure}
\vspace{8in}
\caption{Development times versus temperature Kodak Emulsions}
\end{figure}

\subsection{Elga De-ioniser}

      A schematic diagram of this unit is given in Fig 11.
The procedure is as follows:
\begin{enumerate}

\item Check that the green stopcock (G) on the process
unit is on.

\item Press the button on the side of the control panel
for 'on'.

\item Check that the de-ionised water flow on the 'out'
meter reads about 20 M$\Omega$.   If it does not, the cartridge
SCI needs to be replaced.   Report this to the duty tech
or your support astronomer.

\item The return flow resistivity will increase slowly
to 3 M$\Omega$s but drop quickly when the plate rack is immersed
in the plate washing tank.

\item The inlet and outlet filter valves should read about
40 psi.   If they differ by more than 20 psi the Gelman filter
needs to be changed.   Report this as above.

\item To switch off, it is necessary only to press the on/off
button on the control panel.   No other action is necessary.
\end{enumerate}
\begin{figure}
\vspace{8in}
\caption{The Elga deionising plant}
\end{figure}
\vfill
\eject


\section {PLATE BAKING}

\begin{enumerate}

\item The baking oven (strictly speaking a Gallenkamp incubator) is
kept continuously running in the Chemical Mix room, the second
dark room.   It has been carefully set to run at 65 deg C; if
you find it running at another temperature take some pains to
get it running accurately at 65 C.   Place an empty tin containing
two developing racks in the oven and leave an hour to reach working
temperature.

\item Remove a box of the emulsion you plan to bake from the deep-freeze
in the basement and place in the darkroom to warm up for an hour.

\item Don cotton gloves to remove the baking tin from the oven and carry 
in to the darkroom.   In darkness open the packet of plates and carefully
load them into the developing racks and in to the box so that all
emulsions are towards the label.  Replace the lid of the box
securely.

\item Wearing cotton gloves return the tin to the oven and link it to
 the forming gas supply.   Go to the basement and turn on the Forming
Gas bottle with the tap on the top.   Adjust the pressure to one bar
and note the amount of gas in the bottle.

\item Return to the chemical mix room and open the inlet valve so
that about 8 litres a minute is flowing.   Check that something
is coming through the outlet but the amount is not important.

\item Make out the plate baking log and mark off the plates
removed from the deep freeze in the plate stock book.

\item Conventional baking times at 65C are two hours for IIIaF
and two and a half hours for IIIaJ.   At the end of this period
turn off the bottle in the basement and note its contents for
the baking log.

\item Return to the chemical mix room and turn off the inlet valve.
Open the outer door to the oven and read the right-angled thermometer
through the glass.   Note this value for the baking log.

\item Wearing cotton gloves remove the tin from the gas supply
and remove from the oven to cool.   Make out a record card of the
baking and place in the wallet at the front of the box.

\end{enumerate}

\section {SUPPORTING FACILITIES}

Many of the following facilities are housed in the Chart Room. This can be
found directly opposite the lift door on the second floor of the INT Building.
The Chart Room houses the collection of Sky Survey films and prints, the
Coradograph measuring machine and a Polaroid camera and light table for making
reproductions of plates and films for observing purposes. There is also a
Pericom terminal linked to the VAX 8300 and a Canon LBP-8II Laserprinter.

\subsection {Photographic}

\subsection {Finding charts}

A Polaroid camera is available for making finding charts from Schmidt plates and
films. Instructions on how to use the camera are given beside it. Supplies of
Polaroid film are kept in the metal drawers of the light table on which the
camera is attached. Contact D.H.P.Jones if you run out. Remember that Polaroid
film costs about  1.50 per sheet! 

\subsection {Guide stars}

Although it is possible to find guide stars at the telescope using an eyepiece
as described in Section  , this is a very inefficient use of observing time and
probe positions should always be computed in advance. Guide stars in the
combined astrometric catalogue (AGK3/SAO) may be found using the CHART program
on a Starlink VAX (or on the VAX 8300 in the WHT building). CHART should be run
in either ASTRO or CSI mode with a field size of 1.5 degrees. The program 
{\bf {\sf RGVAD::SYS\$SYSDEVICE:[LPINFO.HELP]JKTGS.EXE}} selects reachable guide 
stars from the OUTPUT.LIS file produced by CHART for any rotator angle with 
the telescope east or west of the pier. If there are no reachable guide stars 
in the catalogue, positions of candidate stars may be input at the terminal. 
The program producces (x,y) probe positions and the relevant position angle 
for any accessible guide stars.

\subsection {Plate measurement}

There is a Coradograph x-y measuring machine available in the Chart Room. It is
in the process of being digitised but can be used with the existing vernier
microscopes to produce x-y coordinates of any size of plate or film.

\subsection {Schmidt prints and films}

These are housed in cupboards in the Chart Room. They consist of the Palomar
Sky Survey on paper down to -30 degrees, the SERC 'J' Survey, the SERC I/R
survey and the ESO 'Quick Blue' Survey. The Palomar set is complete but
additions are still being received to the other surveys mentioned. These are
freely available to all but please take care when using them. In particular the
Palomar prints come packaged with the corresponding Ohio overlay and these
should be carefully replaced when no longer needed. Please take care to ensure
that prints and films are replaced in the correct order in the cupboard. A
misfiled film is as good as a lost film!
\vfill
\eject

\section {APPENDIX}

\subsection {Plateholder and Filter Offsets}

\subsection {Example of FITS packet}

\vfill
\eject

\section {BIBLIOGRAPHY}

This is not meant to be a complete list of all references to astronomical
photography but concentrates mainly on those topics which bear heavily on
photography with the JKT Wide Field Camera. Most of the references are less
than 10 years old and many come from the late, lamented publication Photo-bulletins
of the American Astronomical Society . Efforts are being made to complete the
collection of this journal being held in the John Whelan Library in the INT
Building. The basis of this set of references is `A Manual of Advanced Celestial
Photography' by Brad D.Wallis and Robert W.Provin (Cambridge University Press,
1988). Other useful reference works are `Astronomical Photography' edited by
M.E.Sim and K.Ishida. This contains the proceedings of a meeting at Edinburgh
in 1984 and copies can be obtained from the Royal Observatory, Edinburgh.
Papers containing useful descriptions of hypersensitising techniques can be
found in various copies of Photographic Science and Engineering.

\begin{itemize}

\item{\large{\bf General}}

Albrecht, R. 1980, {\it Measurement and Reduction of Photographic Plates}, 
AAS Photo-Bulletin, {\bf 25}, 9.

Furenlid, I. 1984, {\it Comparison of CCD's and Photographic Plates}, AAS 
Photo-Bulletin, {\bf 36}, 5.

Heudier, J.L. 1981, {\it Astronomical Photography: its present status}, AAS
Photo-Bulletin, {\bf 1}, 3.

Kodak {\it Plates and Films for Scientific Photography }, Eastman Kodak
Company, Rochester, New York.

Miller, W.C. and Hoag, A.A. 1969, {\it Applications of Photographic Materials in
Astronomy}, Applied Optics, 8(12), 2417.

Miller, W.C. 1979, {\it Observatory Photographic Manual: Prcatical and 
Theoretical Considerations Leading to Optimum Results}, Hale Observatories.

Schott, 1986, {\it Optical Glass Filters}, Schott Glaswerke, Mainz.

Smith A.G. and Hoag, A.A. 1979, {\it Advances in Astronomical Photography at Low
Light Levels}, Annual Review of Astronomy and Astrophysics, {\bf 17}, 43.

Wallis, B.D. and Provin, R.W. {\it A look into Photographic Resolution}, 
AAS Photo-Bulletin,{\bf 33}, 4.

\item {Hypersensitisation}

Babcock, T.A. 1976, {\it A Review of Methods and Mechanisms of
Hypersensitisation}, AAS Photo-Bulletin, {\bf 3}, 3.

Babcock, T.A., Sewell, M.H., Lewis, W.C. and James, T.H. 1979,
{\it Hypersensitisation of spectroscopic plates and films using hydrogen gas},
Astr.J., {\bf 79}, 1479.

Hoessel, J.G. 1978, {\it Hypersensitisation of Kodak Red and Infrared
Emulsions}, AAS Photo-Bulletin, {\bf 17}, 10.

Jenkins, R.L. and Farnell, G.C. 1978, {\it Hypersensitisation of Kodak Infrared
Emulsions by bathing treatment}, AAS Photo-Bulletin, {\bf 17}, 3.

Kaye, A.L. 1977. {\it Hypersensitising Kodak 127-04 Emulsion}, AAS 
Photo-Bulletin, {\bf 14}, 14.

Pinto, L. 1979, {\it Experiments on Hypersensitising Kodak IV-N with Silver
Nitrate}, AAS Photo-Bulletin, {\bf 21}, 6.

Schoening, W.E and Hoag, A.A. 1976, {\it Hypersensitising of Kodak IV-N
Emulsion}, AAS Photo-Bulletin, {\bf 11}, 5.

Scott, R.L. and Smith, A.G. 1976, {\it Comparison of Nitrogen and Hydrogen
separately and in combination for Hypersensitising Kodak Emulsions 103a-O and
IIIa-J.}, AAS Photo-Bulletin, {\bf 2}, 6.

Scott,R.L, Smith,A.G and Leacock, R.J. 1977 {\it The use of forming gas in
Hypersensitising Kodak spectroscopic plates}, AAS Photo-bulletin, {\bf 2}, 12.

Scott, R.L. 1984 {\it Hypersensitisation of Kodak I-N Emulsion: Bathing in
Ammonia and/or Silver Nitrate versus Forming Gas}, AAS Photo-Bulletin, 
{\bf 35}, 6.  

Scott, R.L. and Newnam, S.H. 1984, {\it Comparative Hypersensitisation of Kodak
103a-D Emulsion with Forming Gas and Hydrogen}, AAS Photo-Bulletin, {\bf 36}, 3.

Scott,R.L. 1985, {\it Hypersensitisation of Kodak IV-N Emulsion}, AAS 
Photo-Bulletin, {\bf 40}, 3.

Scott,R.L. 1986, {\it Recent Forming Gas and Hydrogen gas flow tests for Kodak
103a-O, 103a-D and IIIa-J Emulsions}, AAS Photo-Bulletin, {\bf 42}, 3.

Scott,R.L. 1986, {\it Hypersensitising Kodak IIIa-F and 103a-E Emulsions}, 
AAS Photo-Bulletin, {\bf 42}, 8.

Sim, M.E. 1977, {\it Hypering of Kodak Spectroscopic Plates with Hydrogen Gas},
AAS Photo-Bulletin, {\bf 14}, 9.

Simpson, S.K. 1983, {\it Variations of Gamma of Kodak emulsion IIIa-F with
Wavelength and Hypersensitisation}, AAS Photo-Bulletin, {\bf 33}, 9.

Solomon, S.J. 1977, {\it Speed gain addition of Nitrogen baking and
pre-flashing of Kodak IIIa-J Emulsion}, AAS Photo-Bulletin, {\bf 2}, 9.

Young, A.T. 1977, {\it Optimum ammoniation of Kodak spectroscopic plates IV-N},
AAS Photo-Bulletin, {\bf 2}, 3.

Young, A.T and Crisp, D. 1979, {\it Hypering Kodak Emulsions IV-N: Ammonia
versus Silver Nitrate}, AAS Photo-Bulletin, {\bf 22}, 3.

Zentalis, N. 1984, {\it Hypersensitisation of IIa-O, 103a-O, IIa-D and IIIa-J
Emulsions by baking in Forming Gas}, AAS Photo-Bulletin, {\bf 35}, 8.

\item{Unsharp Masking and Compositing}

Jones, S.E. 1976, {\it Methods, advantages and limitations of compositing
photographic images}, AAS Photo-Bulletin, {\bf 1}, 15.

Malin, D.F. 1978, {\it Unsharp Masking}, AAS Photo-Bulletin, {\bf 16}, 10.

Malin, D.F and Zealey, W.J. 1979, {\it Astrophotography with unsharp masking},
Sky and Telescope, {\bf 57}, 355.

Malin, D.F. 1981, {\it Photographic Enhancement of direct astronomical images},
AAS Photo-Bulletin, {\bf 2}, 4.

\item{Processing}

Miller, W.C and Bedke, J. 1976, {\it Comparative tests of some commercially
available photographic fixing baths}, AAS Photo-Bulletins, {\bf 2}, 12.

Poland, A.I., and Gosling, J.T. 1975, {\it Reticulation: effects and cure}, AAS
Photo-Bulletins, {\bf 2}, 14.

\item{Sensitometry}

Hoag, A.A. 1977, {\it Sensitometer Calibration}, AAS Photo-Bulletin, {\bf 13}, 
14.

Smith, A.G. 1980, {\it Measurement of absolute photographic sensitivity}, AAS
Photo-Bulletin, {\bf 2}, 13.
\end{itemize}
\vfill
\eject
\end{document}
