

Unlike the iris, it is transparent and one can see the suppressed kawoosh and impact of objects prevented from rematerializing.
THE POWER OF THE ANCIENTS STARGATE GENERATOR
Personal shield: A palm-sized shield generator worn on one's person that projects a defensive barrier.The shield could only be sustained by a single ZPM for just days when under heavy attack from a Wraith fleet, but for 10,000 years under the pressure of thousands of feet of water with only three ZPMs used in sequence. The shield draws a substantial amount of power when under strain. During normal operation the shield can be sustained by one ZPM. When interfaced with a Puddle Jumper's cloak generator, it acts as an invisibility shield and draws less power than it normally would, though it offers no protection other than invisibility. The power required to operate the shield depends on the load it is being subjected to.

Atlantis' shield: The massive dome-like force field protects the city from enemy attacks, extreme weather, and water pressure when submerged in the ocean.
THE POWER OF THE ANCIENTS STARGATE FULL
The Orion's shields, operating at well-below full power, were able to withstand a supervolcano's eruption for 4.1 seconds, while using the eruption to propel it out of its hangar. These shields are incredibly powerful, and have a yellow gold-like color. Aurora-class shields: The shield of Aurora class warships contours around the ship, like an extra hull, instead of an ordinary bubble.Atlantis' sister ship was shown not to have this capability but this is most likely due to the severe lack of power available. Prison cell shield: Ancient prison cells are known to employ shields between their bars to prevent occupants from escaping, as shown within Atlantis as well as their ships.In contrast, the shields of other races, such as the Goa'uld and Asgard, are weakened directly by outside forces, like enemy fire and natural phenomena, causing them to fail or diminish in capacity rather quickly in cases of extreme stress. Ancient shields prove to be almost impenetrable, as long as sufficient power is maintained to operate them. Shields were used by the Ancients aboard their ships and outposts.
