Active camouflage

''This article describes the cloaking technology. For other uses, see Camouflage (disambiguation).'' The term active camouflage (often shortened to active camo or av-cam) refers to various light-bending technologies, both UNSC and Covenant. Most commonly, the term is applied to Covenant-developed cloaking equipment.

Description
Covenant active camouflage technology uses a field of energy to bend light around the user, thus making them effectively invisible. The armor used by Spec-Ops and Stealth Sangheili, as well as that of Arbiters and Jiralhanae Stalkers, include built-in active-camo generators. In the case of Spec-Ops Sangheili, this comes in the form of a "plug" attached to the lower back.

For personnel not equipped with built-in active camouflage, it can be provided by a variety of devices. Typically, the energy used to provide the effect is suspended inside a small, transparent pyramidal container, or a larger spherical force-field. Personnel can use the light-bending energy by coming into physical contact with the container or force-field, which will cause it to break and release its contents. Upon release, the energy envelops the wearer and bends light around their skin; armor or shielding, conforming to their form and rendering them almost invisible. After a short period of time, the energy will gradually dissipate and wear off, slowly revealing its user.

The active camouflage provided by these devices lasts for ten seconds, and only prevents visual detection; those using Active Camo can be observed by other means, including motion tracking, noise, and enviromental disturbances (footprints on soft terrain, etc.).

The UNSC has developed several varieties of active-camouflage technology, including the photoreactive panels of the SPI armor, the texture buffers on UNSC Prowlers and the camouflage cloak. These do not utilize the same light-bending energy as Covenant active-camouflage and are generally less effective.

Function
Active Camo will easily cloak its user, but its effect does not completely extend to items in the user's possession; Human weapons are easily cloaked, but Covenant weapons are visible even with Active Camo, as the light-bending energy cannot mask the glow of the weapons' plasma. In Halo: Combat Evolved, however, plasma glow is hidden quite well by the powerup.

Though Active Camouflage is quite effective from a distance, it can faintly be seen if an observer is close enough to the wearer. However, it is difficult to spot a camouflaged opponent from a distance using a scoped weapon -- actual physical proximity is required to reliably spot a person using Active Camo. It should be noted, though, that Active Camouflage does not mask environmental effects such as footprints, meaning that it is not as effective on soft terrain (such as the snow found in Halo 3 ' s Snowbound and Avalanche Multiplayer maps).

The shielding provided by Active Camo can be disrupted if projectiles pass through it; such a disruption weakens the invisibility effect and temporarily reveals the wearer. The powerup can be disrupted if the wearer fires shots or if the wearer is hit. It also progressively worsens: the longer the wearer fires (or is hit), the more visible they become. Once the disruptions end, however, the wearer quickly regains their invisibility.

Science
Technically, Active Camouflage is not quite invisibility, though it is very similar. Rather, it is the term that is used to describe a broad range of technologies that allows a wearer or object to blend in with its terrain, mimicking the environment around it perfectly, though in two dimensions. There are a variety of ways to do this, though the UNSC uses photo-reactive panels on its Semi-Powered Armor and Prowler warships for optical camouflage, adapting to account for movement.

Though it has never been elaborated on in detail, it is suspected that Covenant versions of the concept use phased array optics to project a three-dimensional hologram of background scenery around the wearer of the system, effectively bending light, a task well within the Covenant's tier two technology level. The technology can be utilized on Human armor systems, such as the MJOLNIR armor, but the UNSC has only developed rough equivalents, the photoreactive panels and the camouflage cloak.

Talc powder and other atmospheric particles can disrupt the systems, causing the technology to overload and fail. The device also generates a considerable amount of heat, causing its user to be clearly visible on Human thermal goggles and some variations of the Sniper Rifle. The humans of Alpha Base on Installation 04 used this advantage when their base was infiltrated by stealth Elites, equipping their Fire Teams with infrared goggles allowing them to easily see the attackers. In addition, William and Kelly employed talc powder in order to overload the camouflage on Reach in order to find them.

UNSC
The UNSC has developed various technologies to conceal a soldier or any object from view. The most common form of this technology operates on a different principle than the Covenant active camo, using photoreactive panels to impersonate the surrounding environment like a chameleon. A device known as the camouflage cloak can hide the wearer's infrared signature, beside serving as a form of camouflage. However, UNSC camouflage technology is inferior to Covenant active camouflage in many respects.

The Semi-Powered Infiltration Armor used by the Spartan-IIIs utilizes photo-reactive panels to conceal the wearer's infrared signature and to blend in with the surrounding environment. When combined with their natural talent and training for stealth, it can be a very effective tool. Some Headhunters use a prototype camouflage almost identical to the Covenant version, rendering them almost invisible, except that it only lasts 3-5 minutes and other systems have their power drained while it recharged. This feature was tested by ODSTs and saw very limited use in 2552.

Active Camouflage technology was later improved and even applied to the MJOLNIR armor system. This camouflage is able to function without ablative panels; the active camouflage is generated by a small device attached to the user's back. This technology has its drawbacks however; all sound is muffled while the active camo is in use, and the more the user moves, the more visible they become.

Much like the SPI armor, UNSC Prowlers use texture buffers or "active camouflage skin" to conceal themselves from view in addition to masking their heat and radar signatures by the use of stealth ablative coating and other systems. This camouflage isn't perfect however, and cannot keep up with a constantly changing background such as a gas giant's atmosphere. However, more advanced stealth ships were developed, such as ONI PRO-49776 using a form of cloak "bubble". This technology has not been observed in widespread use.

Changes throughout Halo
If the Active Camo is active during Campaign, you are completely invisible to the AI enemies unless you fire your weapon. Active camouflage is only usable in Campaign when you are playing as the Arbiter in Halo 2, or you obtain the Envy Skull and restart Campaign(Active Camo replaces Master Chief's flashlight). In Halo 3, rather than Active Camouflage, the slightly different Cloaking is available. It is also available as a powerup in five levels during Halo: Combat Evolved: Truth and Reconciliation, Silent Cartographer, 343 Guilty Spark, Keyes, and Assault on the Control Room.

An interesting fact about Active Camouflage is that although you can see the Sword-wielding Active Camo Elites in Halo: Combat Evolved (due to the sword), the Marines cannot see them; this is likely because the developers didn't realize that the Energy Sword showed through the Active Camo, leading them to code the Marines' AI to be oblivious to it. This advantage is removed in Halo 2 -- the Elites now wait, only activating their swords when they're about to kill you.

Halo 2
In Halo 2, it is noted that the Arbiter's armor, while possessing a built-in active camouflage generator, is not permanent, unlike the more modern generators used by Special Operations Elites. There is a circle on the player's HUD that shows the amount of time left for both the usage of the active camouflage and the recharging sequence. The Master Chief can gain this ability with the Envy Skull on Legendary only; however, his screen will lack the meter, forcing you to remember the time allowed for use.

When playing as the Arbiter, using any attack will cause the active camouflage to deactivate, and the player must wait for it to recharge before using it again.

Halo 3
In Halo 3, the Active Camo is no longer contained inside a pyramid construct. Instead it appears as a large, glowing sphere with what appears to be containment devices around it, enclosing the powerup in Halo 3 multiplayer; but unlike past Halo games, active camo is not found in campaign. In campaign, Active Camouflage is replaced by the Cloaking equipment, which functions in the same way as active camouflage once did. Melee attacks, shooting, throwing grenades and using equipment will negate the effect of the power-up. Also, wearing the Flaming Helmet is an obvious give-away to the opponent because the fire is still visible. By default, the pick-up lasts 30 seconds and doesn't dissapate with movement, unlike in Reach.

The quality of camouflage in custom games may be set to two different settings:
 * Poor Camo: The player has camouflage that might fool a Grunt.
 * The player is still somewhat visible.
 * Good Camo: The player has camouflage that will fool an attentive Elite.
 * This makes the player almost invisible, but the light is distorted within the player's shape.

Halo: Reach
The Active Camo in Halo: Reach has undergone many major changes. It is now available as an Armor Ability to both Spartan and Elite players. As a secondary effect, when used, it acts as a Radar Jammer, scrambling the radar of the user and all enemies within 25 meters, making the user harder for enemies to detect on their motion trackers. This function can be both beneficial and detrimental to the player; on the one hand, it can make enemies easier to ambush, however, it also informs the enemy team that someone is using Camo nearby. This can backfire on the player by making the enemy team more perceptive to possible ambushes. The Active Camo also greatly reduces the volume of all sounds for its user, making it more difficult to notice a grenade being thrown or a nearby enemy firing a weapon. The strength or effectiveness of the Camo also varies depending on whether/how fast the user is moving. When standing still, the player is rendered almost completely invisible. Moving slowly or crouch-walking will slightly decrease the quality of cloaking, although the user is still hard to spot. When moving faster than crouch-walking speed, the Active Camo becomes much less effective, cloaking the user only partially (similar to the Poor Camo from Halo 3). The player's movement speed does not affect the rate at which the Armor Ability meter drains. The freedom for the player to control when they activate their camouflage makes it much more effective, as it allows for use in the most opportune situations, instead of restricting the player to activate it on pickup. However, the reduced hearing and radar jamming effects require the player to be more aware of his surroundings than usual.

Trivia

 * Changing the graphics card settings on Halo PC (lowering the quality and effects) makes active camouflage users appear as an easily-seen gray, opaque silhouette.
 * The Separatist Phantom in Halo 3 has its own Active Camouflage generators on board for various stealth missions.
 * Oddly enough, a group of Major and Minor Grunts in the Halo 2 level Delta Halo used Active Camouflage as they fought alongside a group of Stealth Elites. Spec Ops Grunts are also seen using this in the level The Arbiter just before entering the gas mine. This suggests that at least some Grunts have this equipment.
 * When used in association with an Overshield, the Active Camo becomes completely useless due to the charges of the overshield washing over the player's body (except in Halo: Combat Evolved). In Halo 3, the same effect occurs when Active Camouflage and Overshields are both working.
 * The Active Camouflage has no effect on the flames on the Bungie Armor, allowing enemies to more easily locate the user of the chest piece.
 * With the Envy skull on in Halo 2, the Master Chief's flashlight will be replaced with active camouflage. This can also be combined with a glitch which allows you to reload from a checkpoint, after saving and quitting, and turning off your console, with infinite active camouflage. This makes the Campaign on Halo 2 considerably easier, even on Legendary difficulty.
 * In any Halo game, when you have active camouflage on and you get in a vehicle, the camouflage stays on and appears as if there was a ghost driving it or that it was driving itself (works particularly well with the Warthog LAAG). It works with any vehicle which exposes the occupants to view.
 * In Halo 2 for Windows Vista, when playing on Threshold, your comrades are not picked up by radar when camouflaged.
 * The lights on a Gravity Hammer can be seen clearly when camouflaged. It is not recommended to have a Gravity Hammer either as your primary weapon or secondary weapon when using active camo, as the lights make you an easy target for experienced snipers.
 * In Halo 3, go in Monitor mode and find an Active Camouflage. Go inside it. After about 10-20 seconds, the Active Camo will stop making its shimmering noise and you'll hear a brief whispering sound (like a sigh or breath), and then it will continue its shimmering noise.
 * Strangely, the active camo module in the Halo: Reach Beta had "UNSC" printed on it, even when being used by Elites, though this is likely because it was a placeholder file.

Related pages

 * Overshield
 * Permanent Invisibility
 * Custom Powerup