Good way to farm focus.

[DanujCZ]

As title says. 

[rage4198]

give onto the voi....draco

[Trichouette]

The most efficient way I found right now is draco with a full team based on radial javelin (excalibur's third ability)

 

[bad4youLT]

ivara + redemeer , use same lenses on both ( greates would bes choice ) + xp booster : go to ceres exterminate , kill every grineer were in stealth , keep stealth combo multiplyer and collect focus booster .

 

I manage to get 18,000-30,000 focus per misions , but I seen people get 44,000 per run .

[.xTB_Kenshin]

Spam Excal 3 on draco.

[Rounpositron]

Dracö

[Manyc]

There's a few ways.

Ash using Blade Storm in 4-man squad Draco is a very used one and works with anyone in the team. Making it the most simple and easiest way to farm.

RJ Excalibur, Draco too, although this one may yield better results than Ash, it requires a pre-built team, including an EV trin, buffer..

Ivara, while using prowl, run the highest exterminate mission in Ceres, stealth kill everything while keeping the multiplier on. On this one you either need 2 lenses (frame + weapon like Redeemer or a bow) or if you just want to use the Lens on the frame you're required to use Artemis bow to do the killing. In case of groups you can always put the group asleep which allows you to kill them without having to worry about losing the multiplier.

The above one can also be done with Loki / Ash, using invisibility and running around slide attacking everything on sight with a long reach weapon (ex: Orthos with Reach / Prime Reach), it's a very fast option still using stealth multipliers although since it's fast paced you might lose the multiplier here and there, but the speed makes it worth it.

If you're lazy or rather not be doing very focused / grindy strategies, just try putting Lenses in the loadout you most often use (make it pure 1 school or maybe 1 lens of each and level them all equally) and just go run your regular missions like Alerts / Invasions or regular gameplay overall.

Don't forget that if you want to use the shared affinity to gain Focus, the affinity gained through allied kills gets distributed 25% towards your frame and 75% divided among all weapons you have equipped(1 weapon = 75% each / 2 weapons = 37.5% each / 3 weapons = 25% each) . So if you want to make use of it, try to use only weapons that have lenses and unequip those that don't have one. Sentinels / Kubrows don't take any effect on this.