Ghost

Ghosts are a paranormal phenomenon in the Metal Gear Solid series.

MGS1
Ghosts of the development team appear as an easter egg when certain areas of an environment are photographed with the Camera.

MGS3
Depending on how many people Snake kills in the progress of the game, a ghostly representation of that victim will appear during the boss battle with The Sorrow.

MGS4
In Act Four, development team members and varying FOXHound members can be photographed with the Camera.

The ghosts that can be seen are as follows:
 * Through the wire fence, take a photo of the elevator that Snake took from the Docks in MGS1. The ghost is of Kazuki Muraoka, member of the sound team on every MGS game.
 * Take a photo of the upper-left corner of the Helipad. The ghost of Hideyuki Tanaka, the Japanese voice of Otacon, should be visible in the photo.
 * In the Helipad, the room off the left (which contained Stun Grenades) contains a ghost of a frozen GENOME soldier.
 * Standing directly in the middle of the Helipad, where the Chaff Grenades were, take a photo. The ghost is Nobuyoshi Nishimura, animator and storyboard artist for every MGS game, as well as Zone of the Enders.
 * The ghost of Kenichiro Shigeno, programmer for the series since MGS2, is visible in a photo of the broken security camera by the stairs.
 * In the lower vent which leads to the tank hanger take a photo of the steel directly in front of Snake before the very first right. The ghost here is of Master Miller.
 * Take a photo of the elevator in the Tank Hangar. The ghost of Decoy Octopus is visible.
 * Whilst standing in front of the elevator in the Tank Hanger, as if you have just taken the photo of Decoy Octopus, turn immediately to your right and take a photo of the tank. This will reveal a ghost of a GENOME soldier.
 * In the hallway to the Canyon which contained the laser/gas trap, take a photo of the bottom right corner whilst in it. The ghost here is the DARPA chief Donald Anderson.


 * On top of the rocks to the left after coming out of the Tank Hangar is the ghost of Yoshiteru Kobayashi, animator for several MGS games.
 * In the Canyon where Snake fought the tank, take a photo of the rock area to the left of the door which leads to the Nuclear Warhead Storage Building. The ghost here is Vulcan Raven.
 * From the Canyon, snap a photo just the right of the door to the Nuclear Warhead Storage Building. Yuji Korekado is the ghost here.
 * The ghost of sound team member Ryoji Makimura is visible at the end of the small walkway in the entrance to the Warhead Storage Building.
 * In the Warhead Storage Building, look to the left immediately after entering the main room and take a photo of front of the nuke closest to the stairs. The ghost of a GENOME soldier should appear.
 * On floor B2, take a photo of the hole in the walkway ceiling (where the Gekko entered) to see the ghost of animator Yoshitaka Shimizu.
 * In Otacon's old lab, take a picture of the supercomputers. The ghost here is the ArmsTech president, Kenneth Baker.
 * Take a photo of the Policenauts poster. This is the ghost of Hideo Kojima.
 * The image of programmer Kunio Takabe can be seen in the cubicle to the right of the entrance.
 * Take a photo of the hallway where Gray Fox killed the guards just before Otacon's office. The ghost is Yoshikazu Matsuhana.
 * After beating Crying Wolf, take a picture of the doorway to the right of the doorway which leads to the Blast Furnace or the wolf who appears after you kill/KO her beauty form. As expected, the ghost here is Sniper Wolf.
 * Take a picture of Liquid's crashed Hind D to see animator Hiromi Sato.
 * A photo of the southernmost Communications Tower reveals the ghost of none other than Yoji Shinkawa.
 * In the lower/northern section of the Casting Facility, in the middle is an old furnace that's partially collapsed. Stand to the south of the furnace and take the picture between the two towers to see the ghost of an unknown man.
 * Stand in the centre of the Casting Facility's conveyor belt (in the upper/southern section) and take a photo to see Hideki Sasaki himself.
 * Immediately after emerging from the vent from the Casting Facility, take a photo of the hallway.
 * In the bridge after you fought Vulcan Raven in MGS, take a photo to the waterfall. The ghost here is crew member Yutaka Negishi.
 * The ghost of technical support member Hideo Kimura is visible in a photo taken of REX's railgun.
 * Take a photo of REX's right foot (the foot that killed him) to see the ghost of Gray Fox.
 * Finally, take a photo of REX's head. Still standing in REX's cockpit is the ghost of Liquid Snake.