The following steps are required to place the MK 37 NVS in operation: 1. Place the power switch in the ON position. 2.  Press  your  eye  against  the  monocular  lens eyeshield flap and view the image, or view the image with both eyes through the binocular eyepiece. 3. Adjust the diopter ring to create a sharp reticle image. 4. Adjust the focus ring for a clear image of the object  desired. AN/PVS-8 The  AN/PVS-8  (fig.  2-17)  is  a  portable, shipboard-mounted,  battery-operated  NVS  used  for long-range surveillance. The unit uses the mounting system common to the Mk 37 NVS. An eye shield is used to prevent the visible light emitted from the eyepiece   from   being   externally   visible   on   the operator's face. Power is provided by two 1.5V AA batteries with a life of 60 hours. Magnification of the unit is 6.2X with a 4.7-degree field of view. As with other   NVSs,   an   internal   image   intensifier   tube amplifies available light such as moonlight, starlight, and skyglow, so the scene becomes visible to the operator. An automatic brightness control is provided to   automatically   maintain   the   viewed   scene illumination contrast during periods of changing light level  conditions.  The  manual  gain  control  (tube brightness)  will  not  function  when  the  automatic brightness  control  is  in  operation.  The  image Figure 2-17.—AN/PVS-8 long range night vision sight. intensifier   tube   also   has   protection   from high-intensity,  short-duration  flashes  of  light. OPERATION Setup and operation of the AN/PVS-8 is similar to the Mk 37; actions required prior to installation are as follows: 1. Relieve air pressure inside the carrying case by pressing the core of the relief valve, before releasing  the  latches. 2. Release all case latches and remove the cover. 3. Inventory and inspect the contents to ensure they are ready for installation. Setup of the NVS consists of mounting the sight on  the  appropriate  operational  location  and  installing the batteries. Remove the NVS from the storage case. Secure the pintle in the bracket and locking assembly. Rotate the TUBE BRIGHTNESS control switch fully counterclockwise  to  the  OFF  position.  Insert  the batteries and replace the battery cap. The sight is now ready  for  operation. CAUTION Do not leave the batteries in the equip- ment   during   storage,   or   corrosive damage may result. Do not remove the cover in daylight. The following steps are required to place the AN/PVS in operation: 1.  Rotate  the  TUBE  BRIGHTNESS  control clockwise to turn on the NVS. 2. Press your face against the eyeguard and view the  image. 3. Adjust the TUBE BRIGHTNESS control to the setting  that  provides  good  target  to  background contrast. 4. Adjust the range focus ring for a clear image of the  object  desired. Now that you have the sights operational, you must  learn  scanning  procedures.  A  well-trained operator will see more than an inexperienced one. Targets  that  are  readily  identifiable  by  a  trained observer  will  invariably  escape  detection  by  the 2-16