The Z-90 Photonic Coalescence Emitter/Aegis, also known as the Hardlight Shield, is an Armor Ability featured in Halo 4. Using Forerunner hard light technology, it fuses particles of light into a rigid, dissipative barrier. When used by Spartans, it forms a full-size aegis-class defensive shield in front of the user.
- The Hardlight Shield protects the user from virtually any projectile on the battlefield. The user is still vulnerable to direct heavy attacks such as vehicle splatters and the Mantis' stomp attack.
- The Hardlight Shield can reflect projectiles from various weapons such as Scattershots or Rocket Launchers. If used at point-blank range, the projectiles may even ricochet back to the offending Spartan and count as a kill for the Hardlight Shield user.
- The Hardlight Shield can be used to delay or prevent the user's death until backup arrives.
- The Hardlight Shield does not lose energy when it takes damage. The color change only shows how much longer the shield can be used for, not how much more damage it can sustain.
- While the Hardlight Shield is activated, the user's shields will not recharge and the user will move slowly.
- The Hardlight Shield only protects the most of the user's front. The user is still vulnerable at his sides, back, and a small gap between the shield and the ground.
- You cannot use a weapon while the shield is equipped.
- In Halo 4, Hardlight Shields can be projected by Promethean Watchers to protect Promethean Knights and Promethean Crawlers.
- The Hardlight Shield is the second armor ability in the Halo 4 campaign, located on a raised platform in the center of the room after viewing the Cartographer in the mission Requiem. The first armor ability is Active Camouflage.