Focus Lens

Lens Focus Abilities can be upgraded through the use of, which are earned through the use of a Focus Lens, a special item that converts a percentage of Affinity earned to , before allocating the points to either Warframe only, or split between Warframe and weapon when using a weapon. Focus Lenses can only be installed on Rank 30 Warframes, Weapons, Archwings, Archwing weapons, and Gilded Amps. Only excess experience points gained after Rank 30 are converted to Focus points; if a Focus Lens-equipped item is polarized, the item will not convert Focus points until it has once again reached Rank 30. Items can only have one Focus Lens installed at any time; while players can install another Focus Lens over the old one, the previously installed Lens will be lost in the process.

The type of Focus earned is determined by the lens that is used. For example, installing a Lens on a Warframe will earn  Focus. Affinity earned on a lens-equipped item beyond Rank 30 will go towards earning Focus, and will also take Stealth Attack Affinity bonuses into account. Lens-equipped weapons can earn Focus for direct kills and for ally kills, while Warframes equipped with lenses can gain Focus points from kills made by their powers, weapons, or ally kills. Focus points are converted after Affinity distribution mechanics are performed, i.e. a kill using Warframe powers earns 100% Affinity from said kill (lens on Warframe), thus receiving the full Focus conversion from a regular lens, however weapon kills split Affinity in half between weapon and Warframe, resulting in both weapon and Warframe receiving only half the Focus each per kill. Furthermore, Focus lenses on weapons will still perform the affinity split even if the Warframe has no Focus lens, thus weapons will always receive only half the amount of converted Focus from the player's own kills. On the other hand, affinity from ally kills is shared 25% to the Warframe and 75% shared among all equipped weapons. Unlike with personal kills where unused gear receives no affinity, if any gear has no lens some potential focus will be lost from ally kills.

Affinity earned by other equipped weapons and bonus affinity from completing objectives will not be converted into Focus. Kills made by Syndicate Weapon Augments are counted as Warframe kills instead of weapon kills, and are converted into Warframe Focus accordingly. As of, Focus Points have a daily limit of 250,000, which resets at 00:00 UTC.

Once earned, Focus can be spent by accessing the Focus menu on the Orbiter's Transference Room. Focus points can be spent to unlock a new school, unlock a new upgrade node in an existing school ability tree, upgrade an unlocked node, or increase the maximum Pool for a specific tree.

Types
There are multiple types of Focus Lenses of varying effectiveness available, which can be acquired from different sources.

Focus Lenses
Normal Focus Lenses convert 1.25% of excess affinity gained into Focus points. These lenses can be acquired as rewards from Bounties offered by Konzu in Cetus on the Plains of Eidolon. Alternatively, they can also be traded between players.

Greater Lenses
Greater Lenses convert 1.75% of excess Affinity into Focus points, 40% more than a regular Focus Lens. Their blueprints can be obtained from the Components section of the Market for players who have completed The Second Dream quest. Complete Greater Lenses can also be bought from the Market for. Unlike with normal Focus Lenses, Greater Lenses cannot be traded.

Eidolon Lenses
Eidolon Lenses convert 2.25% of excess Affinity into Focus points, 80% more than a regular Focus lens and ~29% more than a Greater Focus Lens. Their blueprints can be obtained from Bounties.

Eidolon Lens Conversions are used to convert any Eidolon lens into the type of lens the blueprint prescribes. Blueprints can be acquired from Incursions.